Let's say you have a TIE fighter at PS1, moves and lands on an asteroid with his right-side hanging off the asteroid. The rules say he skips his Perform Actions step. However, unlike stress tokens, I can't find anywhere that says he CAN'T act.
So Howlrunner moves at PS8, and has Squad Leader. Can Howlrunner then give the Fighter an action, use it to barrel-roll off the asteroid.. subsequently allowing him to shoot since he's no longer overlapping the obstacle during the combat phase?