CloverBootloader VS libvirt

Definitely look into clover

You need to try and learn it ....clover is a bit eazy then OC https://github.com/CloverHackyColor/CloverBootloader/wiki/Configuration

I did manage to get Clover to boot, turns out it was a graphics card issue (Clover does not boot on ProLiant DL 560 Gen 8) so I threw an old HD 3470 I had laying around in it and I can now access Clover. I gonna play with Clover a little and see if I can get it to do what I want and if not, I grab the Slim ODD to SATA adapter you mentioned. Just need to find the cables to connect it.

In your case you may wish to research using a tool such as Clover Bootloader, which would allow you to install Proxmox to NVMe drives and then put Clover on an internal or external USB thumb drive. The boot process would start from Clover on USB before linking your NVMe installation and continuing from there.

Clover bootloader https://github.com/CloverHackyColor/CloverBootloader

You can use Clover to emulate UEFI on legacy BIOS computers.

Are there any other bootloaders I should be considering? My understanding was that LILO and BURG have essentially been abandoned so even if I were willing to rely on an abandoned project for something as important as the bootloader (I'm not btw) then it probably would not work with LUKS/Btrfs. While doing my initial research, I did come across Clover but I know even less about that than I do about Systemdboot and Refined. My initial impressions is that it seems very customizable theming-wise but it feels like maybe not too many people use it / I'd have a hard time finding help and that's IF it even supports LUKS/Btrfs.

You Clover outdated af (2017). Update to 5123.1, which is the last one with the old memory fixes: https://github.com/CloverHackyColor/CloverBootloader/releases/tag/5123.1

Only in trivial cases. The problem is when another part of the program holds a function pointer (eg callback) into the library which has been unloaded.

libvirt has long been linked with -Wl,nodelete to avoid this:

https://gitlab.com/libvirt/libvirt/-/commit/8e44e5593eb9b89f...

So, next I setup cockpit and cockpit-machines, which works to create VMs (via cockpit-machines) but they use tcg/qemu i.e. emulation and no KVM based h/w acceleration - my test VMs were very slow! I figured out while qemu+KVM works on command line, it doesn't work and the culprit was libvirt! After discussing with the good folks on #asahi channel and with tobhe (Ubuntu-Asahi creator), I gathered enough evidence to conclude libvirtd doesn't know the "right" qemu commands to exec and logged my findings to the libvirt project https://gitlab.com/libvirt/libvirt/-/issues/365 (which can probably use some of the community noise, to expedite the fix).

Nvidia 510 introduced a regression you can see the relevant issues here and here

The work to split into multiple daemons started a few years ago.

https://gitlab.com/libvirt/libvirt/-/blob/9b8bb536ff999fa61e...

There have been a few complaints online in the Arch and Gitlab forums regarding this issue. https://gitlab.com/libvirt/libvirt/-/issues/410

The issue stems from a change in libvirt. Libvirt is responsible for parsing all your VM's XML and turning it into a QEMU command. Somewhere between libvirt version 6.6 and version 6.9, there was a slight change in the way USB devices are passed to QEMU, and obviously libvirt followed suit. As a result, some USB passthrough configurations, such as the MacOS one in the thread, as well as the onboard bluetooth for windows suffered errors.

It's a bug, fix is upstream: https://gitlab.com/libvirt/libvirt/-/commit/04736179b283f55f62616a20a1ec95c665aab8ca