I've been buying these little boxes from AliExpress for years to use as firewalls and routers. My oldest one is almost 9 years old now! OpenBSD installs just fine. Just a BIOS tweak to always boot up after power is restored.
I use one with 6 LAN ports and a fanless 10th gen i5 running OPNsense, and it has worked well for years. It runs many services including Unbound DNS and Suricata with capacity to spare. It's much better than any consumer router, though I run WiFi separately with an Asus AI Mesh set to AP mode.
The only concerns are that you don't get BIOS updates, and you don't know for sure that there's nothing nasty in the firmware. But then you don't really know that on consumer routers either.
Mine died after 2 years after a power cut.
I havent tried to debug it yet. At the time, it would power on but a monitor didnt see anything from the video port, and it didnt seem to actually boot.
I presume it is toast.
If you dont need compact, a rebfurbed SFF with a 4 port network card is gonna be cheaper
pfSense has a very good record, but OpenBSD's record and code quality are literally unparalleled.
Conversely, I spend a fair bit of time working on devices made by SonicWall, Fortinet, etc. and it's all fucking garbage.
Are you concerned about it being designed in China in addition to the conventional and thoroughly ubiquitous "manufactured in China"? Please explain your concerns in detail.