Even More Tacks is the second upgrade of Path 3 for the Tack Shooter in BTD6. It allows the Tack Shooter to shoot 12 tacks instead of 10. It costs $85 on Easy, $100 on Medium, $110 on Hard, and $120 on Impoppable.
A 0/0/2 Tack Shooter can be purchased immediately before a round starts in up to Impoppable Mode, provided the player has at least $650 to start off with.
As a low-cost upgrade compared to the Tack Sprayer, it is a useful lower upgrade for earlier rounds. Of course, the tower can be upgraded to a Tack Sprayer or to a Blade Shooter for even more popping power.
Purchasing Even More Tacks will increase Ring of Fire and Inferno Ring's pierce by 20 (compared to not buying the upgrade). The same applies to More Tacks, except it's only +10 pierce compared to not getting the Path 3 upgrades.
Similar to More Tacks, Even More Tacks adds extra pierce to Ring of Fire and Inferno Ring despite neither upgrade involving shooting tacks. This is likely because the increased number of fire barrels increases the intensity of the flame attack, thus can affect more bloons at once.