Holo caught up with the 3d gap right after Council/Promise id say, with how HoloX only took them only a bit more of half a year to debut 3D, with Promise following very quickly after, there was a definite time where there was a bit of wierdness with the schedules but once they got the ball rolling they literally never fucking stopped, the 3D studio just cemented the ultimate Niji Moggery
I think one of the things i just cant stop thinking about how the two companies dealt with shit, when Fauna had model issues, she was very open about how she had 3D issues related to how the 3d model itself did, but with Pomu, she always gave half hearted answers about her home 3d situation till before graduation where she pretty much barely brought it out for her final Karaoke because it was still bugged to fuck, Pomu had her 3D debut 1 year before graduation, and it was just seemingly never looked at at all
Now, i could be misremembering, but this is how i remember the situation going, where her 3D was just never fixed and only used for official events.