I was also looking for a successor to the PC Engines APUs and came across https://teklager.se/en/ that lists some possible alternatives that you might find interesting.
Personally I was looking to build a router so I ended up buying a fanless N100 based mini PC from Aliexpress (e.g.: search term is "N100 firewall appliance") and have been very satisfied with it so far (Proxmox homelab with OPNsense running as a VM).
Personally I was looking to build a router so I ended up buying a fanless N100 based mini PC from Aliexpress (e.g.: search term is "N100 firewall appliance") and have been very satisfied with it so far (Proxmox homelab with OPNsense running as a VM).