Your right, there's definitely a problem with random barricades around town and it gets annoying but I don't think despawning them after death would make sense. It already gives us a pop up like 5ish mins after asking for 'do you want to remove the props' on that side menu. That and supervisors...
Has this been sorted already? I know you may have fixed or checked it already but what are your specs with your RAM. I'd bet one of your sticks is going bad and you need to run a tester program. Try running on lower specs and activate memory saver for now and see if that helps