I was looking over Splinks' fix for VRC_Stations to make it so that any avatar size that sits in them appears in the proper position with their butt on the chair.

https://github.com/splinks/VRChat-Customizable-Fixed-Chair

I noticed that the main fix was proper baking settings on the animation file for sitting in the custom overrides. I suspect that the sitting animation could be tweaked at VRChat's end to make this fix work globally for all chairs without creators having to go through the rigmarole of custom setup.

https://cdn.discordapp.com/attachments/453927022520172574/511213932267044915/unknown.png

I'm not sure what affect this would have on worlds that already rely on jerry-rigged versions of the chair, and I suspect there would be some broken-looking chairs on already-uploaded worlds, but I think most creators would be willing to re-upload a fix if they knew the chairs were going to work properly for everyone.