A new modifier that transfers the effects of the square to nearby towers or other modifiers of the same type. Each connected tower decreases the effect value of the original square by 10%.

For example, you could put a tower on a 150% attack box, with a 150% range box and then an attack speed of 150. The tower would have 150% attack, 140 range (-10% from origin) and 130 speed (-10 for each transfer) It is not a huge advantage, since you have given up putting 3 towers with all the effects. Additionally, connecting too many towers to a transfer mod could result in negative enhancements. 8 towers connected to a modifier on 150% attack, would suppose 150-80 = 70% damage each tower, 30% less each one.

They can also transfer the improvements of other different modules.
Instead of losing 10% here you lose 1%
Transferring the positive effect diagonally as well, instead of the negative. (+ 15% attack speed, instead of -5% damage)

With enough space a tower could be placed, surrounded by 5 transfer modules and each transfer module could have 4 attack speed modules. This would be very expensive