I suppose the frameworks stabilization is still "in progress" because
not all arch's are stable, but amd64 is, which is the only one I need.
The plasma stabilization did say it was dependent on the frameworks
updates, but it doesn't say anything about why the older plasma (kwin
in particular) seems to be preventing the frameworks update.
Anyway, I decided dto go ahead and accept the testing plasma packages.
I initially put "=kde-plasma/*-5.23* ~amd64" into my packages.accept
file. eix showed (~) for kwin, but emerge complained about that syntax
and didn't accept it. I ended up with "kde-plasma/* ~amd64". I don't
know why the other syntax wasn't ok with portage, but as soon as that
second bug does get settled, I can remove that line, so I'm not too
worried about it being over inclusive.