Currently, the Steam version of VRChat uses version
of the "SteamVR Unity Plugin". VRChat will upgrade to a newer version of this plugin.
SteamVR Input 2.0 gives the Steam version of VRChat access to skeletal input data. It's a requirement for Hand tracking on SteamVR and Pico.
Steam users will gain access to SteamVR's input binding interface, allowing them to customize their controller inputs more easily.