I installed 21.4.0, added the above lines to includes/definitions/unifi.yaml, rediscovered an AP running 5.63.0 (the just released firmware) and it was detected correctly.
He means please contribute your changes to the git site and they can be merged into the project and rolled out to every ones installation. LibreNMS is built by all of us and not by any single company.
We need a more specific OID for this. EdgeMax is 1.3.6.1.4.1.41112.1.5. Looking at it, it looks like Unifi is 1.3.6.1.4.1.41112.1.6. let me know if that more specific one works.
Because LibreNMS matches the start of the sysObjectID (because normal manufacturers group their products by family) unifi can collide with the other two.