Everything works (!!) using Qubes 4.1 20210424 from here: QubesOS 4.1 (alpha) Signed Weekly Builds.
BIOS options: Legacy support, UEFI first, Fast Boot & Secure Boot off, PSP off, OS Optimize Defaults off. No other changes to grub or other configs, no errors (yet) installing or booting. I used a 16 GB SanDisk USB 3.0 stick and the ISO loaded from Win10 using Rufus.
It’s beautiful. Running super smoothly right now, even with only 8 GB RAM (I have a 16 GB SODIMM on the way — maxing out at about ~4 concurrent AppVMs)
In “Session and Startup > General > Logout Settings”, uncheck “Prompt on logout”. I found that clicking it would result in a lound, annoying error beep no matter what the volume settings were.
Attaching a USB to a TemplateVM/AppVM works well, though attaching just the USB’s corresponding block devices & individual partitions wasn’t working properly for me, but I didn’t investigate too closely.
Sometimes using sys-whonix for dom0 updates doesn’t work but sys-firewall still connects (potentially unrelated to Qubes).
Haven’t yet tried suspend or hibernate, as those didn’t work while on 4.0.4
Not recommended. Will boot & install with legacy support enabled, but updating the kernel past 5.4 (in both current and current-testing) kept breaking it with a freeze on boot, requiring a Fedora live USB to mount the EFI partition and change the default kernel back to 5.4 in xen.cfg.