You can also "just" set the 802.11k entries manually. Add 802.11r and you should be mostly good. Usteer makes it slightly better by moving clients to the best AP when they stay stationary for longer whiles.

Yeah, that is actually what the OpenWRT package does, except it grabs the data for me. Saves me the scripting :)

There is a pretty interesting option "nrsyncd" that uses UPNP rather than having to add the 802.11k entries by hand/script. Seems to work quite well, takes a few minutes to gather the information about the other devices. https://github.com/Fail-Safe/nrsyncd/blob/main/README.md