I mean I’ve never seen VRChat load anything from the HDD when switching textures (texture swaps are always instantaneous and happen without hiccups), and I’ve never heard anything suggesting VRChat supports on-demand loading for any avatar resources (in fact I’ve heard the opposite - see link below), so I’m assuming all textures are always loaded into either RAM or VRAM. The “Texture memory” performance metric doesn’t distinguish between different types of RAM, as their placement is usually determined by the engine or platform drivers.
It makes sense though, because imagine if someone creates an animation that swaps textures every frame - while technically they’re never displayed at the same time, they’d still all end up cached in VRAM anyway.
Here’s the link I mentioned earlier