After testing it further I’ve found out that this bug will not crash editor. It will take whole RAM though, in Third Person Template memory usage increases by ~1MB/s, for my project it’s ~4MB/s. It wouldn’t be a problem, but playing in New Editor Window(PIE) or Standalone Game has very low performance, and the only way to fix this is to restart the editor. Also it seems to affect only blueprints that are currently displayed in content browser, so for larger projects the problem gets worse.