Mine was also glued to the heat bed when I broke it… I ended up replacing both the glass plate and the heater because trying to separate them wasn’t worth the effort. A PEI sheet should work okay on the thin aluminum as long as the bed is trammed reasonably well and you can use mesh bed leveling. Otherwise, yeah, stick with glass and be sure to use a release layer.

I got some screw-on bed clips to hold it on at the margins outside the print area instead of gluing down the new one.