Just so I'm following the tagging guidelines properly regarding tagme on official artworks, is there a tag to indicate it is official artwork so that tagme is not needed or would tagging the studio/developer of the anime/game as the circle be preferred before removing?

There was until someone decided there shouldn't be.

https://yande.re/tag_alias?query=official&commit=Search+Aliases

I guess I'll just add the studio/developer to be safe before removing the tagme tags because I linked the official twitter and it was still tagged with it by a mod.