>>103578023
In general terms, they try to keep rigging simple and basic across the board for consistency and to be economical. The whole "3.0 upgrade" thing is a constant because it would feel unfair to older livers/talents if someone immediately debuted with an older model. In practice, this particular case was.... exceptionally bad. Holo has always outsourced their rigging while Niji has an internal team, so the models in Nijisanji have always been "consistently okay" at worst without any major fuckups like this that you get when gambling with external artists. They had to swap to a different rigger from Iron Vertex for Gura's later outfits which finally fixed her face up despite her previous insistence that "it's fine" and "it'll never be fixed".