Crosspathing/Bomb Shooter

In Bloons TD 6, it is important to choose the best crosspathing for a specific tower in order to receive the best benefits out of that tower type. Towers have special roles to play for each stage of the game. The Bomb Shooter in its core is a source of area damage by use of explosive projectiles.

Introduction
Bomb Shooters shoot bombs that explode upon impact. It is slow, but its explosions affect in a wide, circular area. Initially, its explosions have a small blast radius, but certain upgrades can expand the coverage of its blasts. The Bomb Shooter's base range is decent, but it is not normally an important feature for this tower. Bomb Shooters generally attack quite slowly, but they pack a lot of pierce especially with its Tier 3+ upgrades. Path 1 centers the Bomb Shooter dealing high damage, eventually being able to stun bloons including MOAB-class in a wide blast radius. Path 2 focuses on popping MOAB-class bloons. Path 3 focuses on effective cleanup, by increasing range and increasing blast coverage via secondary projectiles.

Tier 2 and below

 * 0-0-0: Can be used as a cheap lead-popping option. Although not as reliable or cheap compared to a 0-0-0 Alchemist, a 0-0-0 Bomb Shooter is the easiest option to choose.
 * 1-0-0: Can be bought for an upgraded Bomb Shooter to hit multiple Leads more reliably, because its explosions gain a greater blast radius.
 * 0-1-0: This slightly increases its reliability to hit fast bloons like yellows and pinks.
 * 0-0-1: It now has larger range
 * 2-0-0: It now has 2 damage
 * 0-2-0: Further increases its fire rate and projectile speed, making it an excellent choice for catching faster bloons far more reliably.
 * 0-0-2: While its fragments are quite weak, the explosions also gain innate black-popping power, making this crosspath somewhat useful in the early-game. The 0-0-2 Bomb is normally for upgrading to 0-0-3 Cluster Bombs.
 * 1-1-0: Combines bigger splash radius with increased attack speed
 * 1-0-1: It may have more range and a bigger blast radius, but that is usually not very helpful because it may miss easily.
 * 0-1-1: Combines greater range and attack speed.
 * 2-1-0: A 2-2-0 without the second increase in attack speed.
 * 2-2-0: Combines the increase in damage and blast radius and even greater attack speed
 * 1-2-0: A 2-2-0 without the increase in damage
 * 0-2-1: A 0-2-2 with out the frag bombs
 * 1-0-2: TBA
 * 2-0-2: TBA
 * 0-1-2: TBA
 * 0-2-2: This lower-tier Bomb maximizes the frag potential by releasing frags more often. It is weak, however, and it is generally more worth just getting 0-0-3 instead or just getting 0-2-0 and some other defense.

Really Big Bombs

 * 3-0-0: Normally, the Really Big Bombs upgrade is merely used as a stepping stone to Bloon Impact. If the extra early mid-game damage is worthy, the Path 2 crosspaths offer greater consistency for the high damage explosions. Placing Really Big Bombs along a bend to maximize its large explosion radius and damage is recommended.
 * 3-1-0: Provides greater attack speed to apply its high damage explosions more often.
 * 3-2-0: Even more attack speed to apply its high damage explosions more often.
 * 3-0-1: Reaches bloons from further, but this is often wasteful for the Really Big Bombs, as it may sometimes miss bloons from afar. In addition, this range boost is not necessarily useful for its attack, as Really Big Bombs is designed to thin out strong waves of bloons, not apply wide-range cleanup as Cluster Bombs would do, and the extra attack speed is a much more useful asset for this purpose.
 * 3-0-2: Adds fragments to each explosion, but these fragments do not deal enough damage to be worth sacrificing over greater explosion attack rate, and fragments lack enough pierce to clean up waves of weaker bloons. The frags crosspath, however, allows its explosions to pop Black Bloons, making this option somewhat useful if needing to clean up more reliably.

Bloon Impact

 * 4-0-0: Bloon Impact stuns affected bloons. By stunning bloons, it gives other defenses more time to handle the stunned bloons. The stun effects are the greatest assets for the Bloon Impact, and as such crosspathing with Path 2 is the more recommended option.
 * 4-1-0: Provides greater attack speed to apply its high damage explosions and stuns more often. If given Jungle Drums, it can permanently stun bloons by hitting the same bloon consecutively, but 4-2-0 is still better because of handling stronger bloons quicker, especially Super Ceramics.
 * 4-2-0: The 4-2-0 Bloon Impact is fully capable of fully soloing a Super Ceramic when given sufficient time and supported by Striker Jones Level 5+ or a Monkey Intelligence Bureau.
 * 4-0-1: Reaches bloons from further, but this is often wasteful for the Bloon Impact, as it may sometimes miss bloons from afar. In addition, this range boost is not necessarily useful for its attack, as Bloon Impact is meant to stun from a closer range, and 4-2-0 Impact already has a generous range.
 * 4-0-2: Adds fragments to each explosion. While these fragments deal more damage, they do not deal enough extra damage to be worth sacrificing over greater explosion attack rate, and fragments lack enough pierce to clean up waves of weaker bloons. Explosions with this crosspath do pop Blacks, which trades permastuns for better mid-game cleanup.

Bloon Crush

 * 5-0-0: Bloon Crush is just like Bloon Impact but it deals 4x more damage and can stun MOAB-class bloons. Regardless of crosspathing, Bloon Crush stuns bloons for long enough that any consecutive hits will permanently stun them. But even then, Path 2 crosspathing is much better for the more consistent stun, especially when countering greater clusters of blimps and bloons.
 * 5-1-0: See 5-2-0
 * 5-2-0: The superior option due to refreshing stuns much faster, especially once its explosions begin to hit the pierce cap and would subsequently overwhelm a Bloon Crush.
 * 5-0-1: This crosspath is wasteful because Bloon Crush is supposed to keep blimps and bloons within the same location.
 * 5-0-2: Bloon Crush fragments are much, much stronger than the explosions themselves, but they have very low pierce in comparison to its price, and this misses out on the faster stun refreshment in case the Bloon Crush begins to get overwhelmed. Bloon Crush explosions already pop Black bloons, making this crosspath already redundant.

MOAB Mauler

 * 0-3-0: MOAB Maulers pack with high grouped MOAB-class damage for a cost-effective price. It is usually better to go straight for this upgrade and then crosspath it, rather than to pick a crosspath and then upgrade to MOAB Mauler.
 * 1-3-0: The extra blast radius is helpful for the MOAB Mauler to hit more blimps per shot. Primary Mentoring allows a group of maulers to buy this upgrade for free.
 * 2-3-0: If blimps are very dense, 2-3-0 is a worthy crosspath to go for. But in most cases, spamming 1-3-0 Maulers near a Primary Mentoring is better, as Maulers are designed to counter groups of MOAB-class bloons rather than dense clumps of normal bloons.
 * 0-3-1: Useful if Maulers need to shoot further, which can be handy on certain maps. As with 1-3-0, Primary Mentoring allows this crosspath to be bought for free.
 * 0-3-2: Gives a small range boost compared to 0-3-1, but the fragment attacks deal insignificant damage to MOAB-class or Ceramics. In the case where there is no Striker on screen, this crosspath is more efficient for dealing with DDTs than to add an extra MIB, because frag explosions do pop Black properties.

MOAB Assassin

 * 0-4-0: If used only for the ability, this crosspath is useful. Crosspathing does not affect the ability at all, but crosspathing helps boost its main attack damage against both MOAB-class and Ceramics.
 * 1-4-0: The extra blast radius is helpful for the MOAB Assassin's main attack to hit more blimps per shot. MOAB Assassins deal greater damage to Ceramics too, so this upgrade can help against that too as a bonus.
 * 2-4-0: If blimps are very dense, 2-4-0 is a worthy crosspath to go for. Also applies to Ceramics to a lesser extent.
 * 0-4-1: Useful if Assassins need to shoot further, which can be handy on certain maps. MOAB Assassins have plenty of range already, however.
 * 0-4-2: Gives a small range boost compared to 0-4-1, but the fragment attacks are insignificant. Like Maulers, having the Frag Bombs upgrade allows explosions to pop Black properties.

MOAB Eliminator

 * 0-5-0: If used only for the ability, this crosspath is useful. Crosspathing does not affect the ability at all. As with Assassin, crosspathing helps its main attack better utilize its improved MOAB-class damage.
 * 1-5-0: Like MOAB Assassin's main attack improvements, but to optimize the huge MOAB-class damage bonus.
 * 2-5-0: Just like 1-5-0 MOAB Assassin but for even denser clumps of MOAB-class.
 * 0-5-1: Similar principles applied from 0-4-1 MOAB Assassin.
 * 0-5-2: Frag attacks are insignificant, but MOAB Eliminator already pops Black by default anyway, making this crosspath redundant.

Cluster Bombs

 * 0-0-3: Useful if needing to demolish weak dense groups of bloons with a Bomb Shooter for cheap. Crosspathing is beneficial but not vital for Cluster Bombs. Path 1 offers superior grouped damage, while Path 2 catches faster bloons better and has a better synergy with buffs.
 * 1-0-3: More explosion radius and a considerable increase of pierce for each cluster.
 * 2-0-3: Generally the go-to upgrade for the much greater pierce and a bonus +1 damage per explosion including its secondary explosions.
 * 0-1-3: Attacks faster, thereby creating clusters at a faster rate too. 0-2-3 further improves on this.
 * 0-2-3: Attacks faster, thereby creating clusters at a faster rate too, but 2-0-3 has the superior damage output. There is a greater synergy of 0-2-3 Cluster Bombs with Alch buff, but 2-0-3 with Alch buff is still better for greater breakdown of stronger bloons and the faster attack rate. 0-2-3 can catch Yellows and Pinks better, however.

Recursive Cluster

 * 0-0-4: Every second shot from Recursive allows tertiary clusters to be produced, which possess extremely high pierce. By this point, Recursive Cluster should've gotten a crosspath choice already. Upgrade it to Path 1 for more pierce and damage, or Path 2 for more attack speed.
 * 1-0-4: More explosion radius and a considerable increase of pierce for each cluster. Here, the explosion radius matters the most, as this mainly affects the tertiary explosions.
 * 2-0-4: Generally the go-to upgrade for the much greater pierce and a bonus +1 damage per explosion including its secondary and tertiary explosions. This is far the best option to deal with grouped ceramics
 * 0-1-4: Improves the rate of creating its tertiary clusters too. 0-2-4 further improves on this.
 * 0-2-4: Improves the rate of creating its tertiary clusters too, but 2-0-4 has the superior damage output. There is a greater synergy of 0-2-4 Recursive with Alch buff, but 2-0-4 is still better with Alch buff for greater breakdown of more bloons due to its much larger pierce. In fact, the only situation in which an alched buffed 0-2-4 is better than an alched buffed 2-0-4 is against a single target, where recursive struggles anyways. 0-2-4 triggers tertiary clusters more often, and occasionally this part makes it better than 2-0-4 in the case where groups of bloons move quickly.

Bomb Blitz

 * 0-0-5: Bomb Blitz usually needs a crosspath to function as a damage source, but if used for only the passive ability then a 0-0-5 Bomb Blitz is still useful. Note that the passive ability is completely unaffected by crosspathing.
 * 1-0-5: More explosion radius and a considerable increase of pierce for each cluster. Extra blast radius shouldn't matter because it already reliably pops bloons it is close to and covers a wide explosion radius via consistent tertiary explosions per shot. On top of this, tertiary clusters have a very high pierce already. Path 2 is better for Bomb Blitz as a DPS option.
 * 2-0-5: It isn't a "useless" crosspath, but it is less efficient DPS compared to the 0-2-5 for reasons explained in 1-0-5 plus the fact that +1 damage doesn't scale as well compared to the +66% total attack speed.
 * 0-1-5: Improves the rate of creating all explosions, including secondary and tertiary clusters. 0-2-5 further improves on this.
 * 0-2-5: Because each individual explosion deals much more damage, the attack speed bonus scales more than the +1 damage. Adding Missile Launcher offers +66% total attack speed compared to not getting any Path 2 upgrade.

Strategy
Bomb shooters Tier 5 upgrades are unique due to the fact that they all fill a