@jollysea Most of the time it just works. Using it with an external controller (either 8bitdo bluetooth, or Switch Pro Controller via Mayflash NS) is pretty smooth, but I've found no way to access the quick settings menu (the one that pops up if you press the right "..." button) - normal "STEAM" menu works fine.
Have to get up to push the button to turn it on!
Games seem to be upscaled from 720p to whatever resolution the external TV (FullHD / 4k) - but that might be a settings thing?
@noiob @jollysea ahh thanks for that info! (It's home+B for the switch controller because of the different layout)