Valve has long been preparing its software stack for the arrival of both the Steam Machine and the upcoming Steam Frame, and the latest update sees the gaming giant add a long list of fixes, QoL improvements, and features to SteamVR as well as the developer back-end in order to prepare for the Steam...
Thanks, you typed more than I was going to :)
Only note is FEX and the Android compatibility layer were two separate goals Valve put a lot of work into, so I wouldn’t classify it as a side-effect.
One is to allow Windows games to work on the Frame, the other is to allow Android games to work on the Frame