Same exact issue on my Hermes Series 10. I have a genius bar appointment today and I’ve heard experiences where apple will give you a new watch. If not, I will likely wait until Beta 3 drops. Using airplane mode also helps to conserve some battery, but again, it really only reaches 80% charge even on low power mode and dies within a couple of hours.

I believe beta 10 has fixed the problem!! It may have also been using Recovery mode. I updated to beta 10, but still had an issue and was only able to boot in "safe mode." I then restarted in Recovery Mode (CMND + R). I did a disk utility and the operation was successful. Then I re-installed macOS big sur. Problem was still not solved, the reboot hung again and I needed to boot in safe mode. However, the re-install re-installed beta 9. I installed the beta 10 update from System Preferences and beta 10 booted up fine! Running normally now!

@skoskie808 - I haven't tried contacting Apple other than via the Feedback Assistant (no response) or through here. Thankfully I have my iMac which works perfectly on beta 9, and my MacBookPro still boots in Safe Boot (and everything is backed up, from about a month ago with beta 4 or 5 (so at least my photos and hard drive data is "safe")). I would definitely be in a much *much* worse position if my MacBookPro was my main computer/work computer, but thankfully it is my personal computer, so I can live with having it only work in "Safe Boot" for a couple of weeks. REALLY hoping a new beta and/or the GM is released tomorrow or at the Tuesday event...

SAME ISSUE WITH BETA 9, released today!

@munozoga22  The way that I was able to get back onto beta 6 was by restarting my computer in safe mode and then going to deverloper.apple.com and downloading the Install Profile again. This had my computer re-install macOS Big Sur cleanly (the 12.16GB install), which installs beta 6. My computer then said I had an update available (but do not update (turn automatic updates off) and stay on beta 6 until a more reliable build is released. Still no fix on how to get to beta 8... it simply will not install properly