Over at Tom's hardware they spotted ECS mini PC with AMD based A320 motherboard.
As the model number implies, the SF110-A320 features an AM4 motherboard based around the A320 chipset. According to the listing, it supports Ryzen 3 and Ryzen 5 APUs as long as they confine to the 35W envelope.
I hope this comes available to the US. There's a Chinese manufacture, Onda I think, that's making a thin-mITX A320 board, but you have to buy it from a Chinese website and deal with customs and such. It'd be great to have something with more local distributorship, and since ECS has a presence here, one can hope!