I bought a used thinkcentre tiny off of eBay. It's got great GPU decoding/encoding support, great driver support for all the peripherals, and can boot from an m2 NVME or a SATA drive, it has a very normal bootloader. It can even run Windows. The mostly-aluminum enclosure is very nice and well-engineered, it's easy to pop open, it has a power button. It was under $100 and makes me question why any hobbyist bothers with SBCs like these.