does anyone have advice on the best way to go about finding and fixing Various Artists compilations that don’t have the compilation subtype set? These are constantly messing up my lookups from Picard, because I have it set to find albums over compilations - but if the compilation isn’t marked as a compilation Picard doesn’t know any better.
(This is where better release filtering in Picard would help a lot, too…)
Do you mean how to search for them?
VA albums not set as compilations
Not all of those should be set as compilations though.
Yeah, that’s the trouble, right? Can’t just set them all automatically. But there are too many which need to be set that aren’t, too.
artist:“Various Artists” AND primarytype:“Album” AND -secondarytype:“Compilation” AND -secondarytype:“Soundtrack” AND -secondarytype:“DJ-mix” seems a bit better in having actual compilations on the results but it doesn’t help that much. I think the best option here would probably be to have a script that gives you a button to click that submits an edit setting the compilation type from the search. Maybe @jesus2099 or @loujin or someone are interested on writing that? It’s probably relatively simple 
That would be awesome! Although I’d still be hesitant about using it willy-nilly…
Well you can still open it in a new tab if not completely obvious, but for many of them it’s just too clear. Fixing a few classical releases that came up there, now 
And the @reosarevok’s suggested search made into a link:
https://musicbrainz.org/search?query=artist%3A"Various+Artists"+AND+primarytype%3A"Album"+AND+-secondarytype%3A"Compilation"+AND+-secondarytype%3A"Soundtrack"+AND+-secondarytype%3A"DJ-mix"&type=release_group&limit=25&method=advanced
Maybe “Remix” should also be excluded?
Edit: Gadeplan was the #1 hit on the above search for me, but not a Compilation. The Release Group artist had never been fixed to match the Release artist. I fixed this now (for this release/release group), but it might be worth to make a check that the Release artist is also VA before automating setting RG secondary type to “Compilation”…