I think Perfect Control DOES technically work... but seemingly only towards the target it was initially fired towards, which all too often is long dead by the time the projectile gets close. Even with some projectile speed upgrades for Sparky AND reducing Icy's projectile speed. So before reaching a wave where enemies actually get to live for a bit this upgrade is... basically a wasted choice with how little it does?
Ricochets may or may not be affected, I really can't tell.
Was really expecting it to allow for switching to new targets as well.