I can confirm the Beta 2 update fixes the previous issues on the AWU. If you haven't updated yet, do as soon as you can.

I'm afraid there's no way to downgrade on your own; I've seen a few people on Reddit saying that it may be possible to book an appointment at an Apple Store and request a downgrade there, but I don't know if that's still a thing, or if they'll be able to do it for you on the spot. Also, I can confirm that resetting to factory settings does not work. Two things I've noticed: (1) if, like me, you're precious about your move/exercise/stand streaks, keep an eye on your watch throughout the day: the tracker seems to get stuck at random times, so for the next ~2 weeks (until we get a new update that will bring our Apple Watch Ultras back to "normal") you may see a few gaps in your activity, gaps that may last hours; (2) if you have a Sleep schedule that turns on automatically, you may want to turn that off for now: when it's on, there's a higher likelihood that the sleep tracker will cause the watch to freeze overnight, and in the morning your watch may freeze as it transitions out of the Sleep focus. For now, I'll use a sleep tracker on my phone instead.

Thanks -- I have two submissions: FB11997109: Accessing Control Center causes watch to freeze FB11997132: Pressing the crown, scrolling with the crown, or using the side button to use the watch while it’s charging causes the watch to freeze Let me know if you need further details or submissions.

Thanks -- I've followed the instructions and tried to reproduce three issues: checking Notification Center after a reboot (result: AW Ultra freezes); trying to use Apple Pay (result: AW Ultra freezes); trying to open anything from the App List (result: none of the apps from the App List open anymore). The Action button (needed to trigger sysdiagnose) causes the watch to freeze. I've waited 20 mins now, but the logs don't appear. Is there another way we can file and escalate this feedback?

I can confirm I'm seeing the issues reported by @areapa058 on my Apple Watch Ultra too: unresponsive touchscreen when trying to access Control Center, when trying to adjust the brightness of the screen, or when rotating the Digital Crown anywhere; unresponsive Digital Crown: the haptic feedback works occasionally, but it's not consistent; widgets not loading with major delays (3-5 minutes for the homescreen widgets to finish loading content after turning on the Apple Watch); frequent reboots, even when the Apple Watch is not being used; notifications aren't coming through -- Notification Center remains empty; "Wake on Crown Up" doesn't work anymore; "Wake on Wrist Raise" triggers the watch face to wake after a delay of 2-3 seconds; Apple Pay doesn't work anymore in this build: Wallet either shuts down or goes in the background when double-clicking the side button to pay, making Apple Pay unusable on the watch; the "Action button" causes the watch to freeze regardless of which action it's linked to (start a workout, start Backtrack, etc.); the only way to get out of this screen is to hard-reboot the watch.