Trap Behind Corrosive Cube
A trap/enemy can’t see through a corrosive cube, but if you go where trap “sees” you, it would activate and can go through corrosive cube (except if corrosive cube got the mod which makes him “solid”).
Same for the enemy and projectile. Thats why corrosive cube + bolters (traps or ennemies) is a pretty strong combo.
You can get traps to activate behind the lava cube only if I set the lava cube to “appear on second wave”. Suddenly my bolds behind the cube will now fire through it. Before the bolts won’t fire.