The flagship APs like U6-LR from Ubiquity are a bluff package, since they are only equipped with an 1 Gbit/s port.
Currently, there is no product on the market for use cases, where mainline OpenWRT support is necessary. For instance, the Freifunk community in Germany builds mesh networks over whole cities using a firmware built on top of OpenWRT.
Also, there is the self-sovereign and open source cloud management system OpenWisp for APs running OpenWRT.
There is currently a market gap of Wi-Fi manufacturers providing enterprise level APs with mainline OpenWRT support for this kind of installations.
To give you some numbers: In Germany, there are >10,000 APs operated by Freifunk [source].
I’m sure both of these projects would be happy being able to finally have a manufacturer that builds for their needs.
What do you think about it, @alzhao ?