> This makes me wonder if a #flash would help for that scenario..
>

Yes that would probably help. Although I do think that this is a preference
that might best be left disabled by default.

How about gaining a month of context using it before making that judgement?  I have full context of working under both settings, which is how I'm able to understand the rationale for it.  It seems like you could be "reacting" from your trip to the corner-case.  If you happen to go there again someday you won't get confused because you know about it now (plus I like the #flash idea, which would make that certain).

OTOH, window proliferation has been a common complaint of Smalltalkers for years.  Just recently on the Pharo list, in fact.  Squeak can show that it has addressed that complaint elegantly, and so it should.