In general terms, I think a flip from a trap will always be weaker than a flip from the rest position. When you flip from a trap, not only will the flipper get less travel or power from the high power coil before the EOS switch opens and cuts power, but you also have to overcome the momentum of the flipper assembly moving in the wrong direction. Starting from the rest position the flipper gets the full benefit of the high power coil before the EOS switch opens.

Either way though I don't think you should have trouble reliably knocking down a target from a trap, even at the top of the playfield. Targets at the edge might get hit a little harder than those in the middle but the flippers ought to be able to send the ball with enough speed to do it. Is there any extra slop or friction in your flipper assemblies? Are the return springs too tight? Does the EOS open too early?

/Mark