This is a real pain point with OpenWRT, made worse by the developers' concept that there are "proper" ways to do it (which are supported by almost no other software) and so the workaround is either to do the dance or replace everything with OpenWRT that will do it "properly".
Defensible idea, but the reality is that most people who are willing to do this in the first place are trying to reuse an old router as a low-usage wireless bridge on a network that is otherwise centrally controlled like Unifi or Omada. My pool controller would be fine to run on 802.11b (setting aside what that would do to the rest of the wireless network), it doesn't need a WiFi 7 device.
But its also really feature rich and with a bit of effort you work it out and you have that longevity and the security issues fixed long term, much further than the manufacturer is willing to support it.