It’s a gigabyte ab350m gaming-3 rev 1.0. it boots grub fine but then crashes right after displaying “loading Linux 6.x”, CPU led flashes then dram led stays on, I have to turn it off with the PSU switch.
Either it’s a rev 1.0 bug which is a thing on those motherboards, or the CPU (or igpu) is defective.
https://superuser.com/questions/1854228/proxmox-doesnt-boot-after-cpu-change
I’m currently waiting on support from both the seller and gigabyte but I don’t expect anything out of it, though I’m still yet to test it in a different motherboard.
This resizing is done by pictrs at runtime, when you request the image. Unless the external image host also uses pictrs, you can’t do this with any other host, no.