> The HiFive Unmatched has been around since early 2021, is fully documented, supported by many OSes, does not have a proprietary GPU, has a PCIe x16 connector

> The HiFive Unmatched has been around since early 2021, is fully documented, supported by many OSes, does not have a proprietary GPU, has a PCIe x16 connector with 8 lanes active, was $665 but is now $299, which is under your $300. Did not know this, thanks! I do wish it was at least PCIe 4.0 (RX 6400 has 64-bit memory, which is a bit choked on 3.0), but that's a minor gripe.