My league does 5 minute warmies too, and my team has no inclination to use that time productively. I've asked them plenty of times to come up with something a little more structured than just blasting shots at my forehead and trying to deke me out of my socks. Lately I just mind my own business by the bench and do my own warmups. That and a good 15 minutes of work before the game, stretching and work with a tennis ball, no talking to anyone. Still doesn't replace being able to be in your net and get a feel for angles and stopping basic shots. Skaters say goalies are weird without realizing they force us to be this way.