Currently, Picard uses the "default" artist sort name, no matter what the artist credit says. (Artist credits do not have sort names.) This isn't accurate when editors try to merge "name variations" into a single entry (which is sometimes actually against the guidelines on separate projects).

The "default" artist sort name field was supposed to be deprecated in the future. This is similar to how Labels used to have a "default" sort name field, but it was nixed after aliases were added to Labels (mentioned in MBS-11343). So I figure the ability to be "smarter" about the artist sort name is something that would eventually need to happen (in the distance future) anyway.

For each artist and "credited as" text an artist credit, It would be possible to search through an artist's aliases, pick the alias (depending on the user's preferred locale) that string-matches to the "credited as" text, and use the sort name from that alias. This would make it possible to have more "accurate" sort names that differ depending on the name variation used in the artist credit.

(The only issue this doesn't solve is that each "join phrase" in an artist credit would remain un-localized. However, that is how Picard currently behaves with the "default" artist sort names anyway. For example, https://musicbrainz.org/artist-credit/1169307 ends up with a sort name of "RAMMに這いよるKūkoとKūne".)