Should I scrape all the propolis off before winter or leave it — the bees put it there on purpose, right?

Third year in Uppsala, three hives, and everything is glued. Crown boards need a hive tool at every corner, the frame lugs are welded to the runners, one colony has narrowed its own entrance with a propolis wall, and another has sealed every gap around the mesh floor tray. My instinct says leave it. It's their draught-proofing and it's antimicrobial, and if I scrape it off in September they'll just spend resources putting it back when they should be clustering. But a veteran at the club says scrape everything now, because in spring the boxes won't come apart cleanly and I'll tear the crown board. Is there a sensible middle ground — scrape where it fights me and leave the rest? And is autumn even the right time, or is this a spring job?