It would be nice to have this as a settings option in VrChat since a full Vram is a major issue in bigger lobbies, and nothing more ruins the overall experience than needing to hide people's avatars and look at grey robots.
A texture size limit is applied to all textures.
Setting this to one uses the first mipmap of each texture (so all textures are half size), setting this to two uses the second mipmap of each texture (so all textures are quarter size), etc.. This can be used to decrease video memory requirements on low-end computers.