Based on https://community.metabrainz.org/t/composer-translate-into-local-language/457229:

Composer = "Дмитрий Дмитриевич Шостакович" (= Dmitri Shostakovich)

• "Translate artist names to this locale where possible": not activated
  Result in Picard: "Дмитрий Дмитриевич Шостакович".
  => OK.
• "Translate artist names to this locale where possible": to "German" is activated
  Result in Picard: "Dmitri Dmitrievich Shostakovich"
  => NOK (?!?)
  It's not clear which translation will be used here. It is not the German alias.
  It's even not an alias but can be found as artist credit for the composer. I can not find it on release, track, recording or work level.

First it's not clear at all if and how "Translate artist names to this locale where possible" affects on Composer. Is Composer also an artist, i.e. is it in the meaning of the entity or in the meaning of a performing artist?
However, this option causes a translation also for the composer.
Since I've selected German I expect a translation to German.
There is also a a primary German alias defined.

For me it's wrong to have a translation to ??? if German is activated.
First it should be clarified if the translate option will affect only the artist field or also all other roles (composer, vocals, etc.).
If the translate option will also work for other roles then the selected language should be used, i.e. the primary alias for this language.
If not, then there should be no translation.

BTW: There is no "Credited as" for the composer at work

Overall the translation feature is not transparent, it's not clear for me when a translation will take place.
Personally I'd prefer an option to have translation only for entities work (and maybe recording), but not on release and track level (where I'd like to get the "credited as").