If all you're looking to do is avoid Ubiquiti breaking GPL not necessarily binary blobs/100% open I'd recommend just using the Intel AX200. It's 20 bucks, will have longer support, supports AX, and supports more features/extensions on older versions of Wi-Fi than e.g. their AC chip does to boot.
Linux / OpenBSD with open source wifi drivers, if that is even a thing. Snatch some Atheros or Realtek chips before they disappear.
https://en.wikipedia.org/wiki/Comparison_of_open-source_wire...