There’s not much of a point to going beyond 1080p for the steam deck screen, nor is there for going above 60 FPS (until the OLED version ;) ).

Sunshine has AV1, but there’s not many hardware encoder available for AV1 that aren’t near top of the line video cards (GTX 4xxx series, latest AMD series). the h264/h265 codecs are faster anyways which is important for the latency here (vs. streaming a movie).

The best thing you can do is make sure your network setup at home is top notch. Upgrading my WIFI router did wonders for moonlight streaming to my deck.

You could also convert from HDMI to USB with an adapter - https://www.amazon.com/ELUTENG-Thunderbolt-Compatible-Converter-Connector/dp/B07Z4G911X/ref=sr_1_5?crid=28KA3BK1OUGRY&keywords=hdmi+male+to+usb+c+female&qid=1699996385&s=electronics&sprefix=hdmi+male+to+usb+c+female%2Celectronics%2C117&sr=1-5

UO was not one of the things I was expecting to see scrolling through this. Takes me back to my weird ass galloping horse movement I had because I played on a 56k connection…