"I've got a 'chute, so I don't need/won't bother to maintain proficiency in pfl's" becomes a self-fulfilling prophecy: if the engine quits for real, you pull the 'chute because you're not in current practice.
Remember also the need to keep current in case the engine quits below 'chute deployment height. Establishing the aircraft in a glide configuration still needs to be an automatic reaction if it suddenly goes quiet.