In some cases the type of magic resistance affects what can be done. The example in the most recent book might not have worked on Lord Raith or the Scarecrow, as they might have a version that just dissolves any kind of magic, including things created by magic, where the trick Harry pulled could well be based on his analysis of the specific kind of countermagic used by the critter in question in Skin Game.
On a related topic, physical immunity clearly doesn't mean you can't stick aspects on the critters with physical force. There's evidence of that in the last book too - but it does again depend on the flavor of the immunity. To pick an easy example, if a demon is immune to fire, you could still perhaps blind it with a bright light or a cloud of smoke - but both maneuvers could be defeated against the wrong kind of demon (a sun demon is unlikely to be affected by bright lights, a smoke-elemental can likely also see through smoke in addition to being immune to fire).