Unfortunately my first play with #AndroidDesktop was a bit disappointing. The phone seemed to output only 1920x1080 to my monitor which stretched to fill the ultrawide aspect (setting a higher resolution in the phone was available, but this only appeared to render at the higher resolution before scaling down to 1920x1080 for the external monitor).
Some features feel undercooked so far - you do need to modify the screen turn-off time for it to be usable. Some popups (e.g. changing audio output so I could use my USB headphones connected to the monitor's hub) have to be interacted with on the phone, and some settings require you to authorise via PIN or biometric (whichever you have set up) . Also some apps needed to be restarted to run at a reasonable resolution on the desktop. Firefox does not yet appear to be able to avoid scaling the content to a more reasonable resolution, and Chrome only did this when it was launched from Desktop mode.
Still, it was convenient being able to use a keyboard and mouse with my existing apps, and I was able to play media through it fine. I'm curious if this evolves to be less awkward and whether it might make a handy fallback if I had to hotdesk at a friend's place perhaps, or playing video through hotel TVs etc.
Looking forward to this mode coming to GrapheneOS-powered Motorla phones soon! 馃槈