Another detail... hopefully the last...
Right now I have a LOT of entries like this:
(!) says this:
There's a sort composer value entered, based on tags, but it hasn't been applied to the thumbnail browser, and resaving isn't enough to apply it. I actually have to delete, save, and reenter it, or use the popup to make it work. If there's a sort composer value in tags, shouldn't it automatically be applied as composer:etc...?
Also, if I go into the pop-up and enter the sort composer I want, with "composer:", it is applied correctly but the sorting tab just shows the regular name, which is a little disconcerting, especially since once you save the value, there's no way to access it again from the Sorting tab. It doesn't show up in the Sort As box, and there's no button for the pop-up - or if there is a popup due to other tags, the "composer:" entry isn't shown there, anyway.
I would expect that if there's a "composer:" sort value, it would be shown in the "sort as" box for composer, and that if you enter a value in "sort as" for composer it should either automatically be turned into "composer:" or there should be a way to indicate that you want to do that. And if not that, it should at least definitely show up in the pop-up list.
Oh, and a tiny but irritating bug: you can't enter a space in the Composer field on the Sorting tab. As soon as you press Space, the cursor jumps to the beginning of the field. So you have to go to the main tab to enter a composer.
Edit: One more bug I've come across - it's possible to trigger the save & go to next hotkey while you have the "edit custom sort values" pop up open.