OK, so adapter has arrived, I can say it works, but it's not way straight forward to get it work and I'm not 100% sure if it will be usable.
Thing is that device first was diecovered as one radio and easily I got it working on 2.4Ghz as AP.
Clients connected, all was good. But I was hoping to switch to 5Ghz. So I disconneted, switched to 5Ghz mode, to right channel etc. And after restart, device didn't work. Radio interface was still down.
Last hour I spent reseting, changing settings, plugging it to another USB port etc. There were moments of success. I got it working as 5Ghz AP and I connected clients. But after another settings adjustments it stopped working. Apart of that, somewhere in the middle, second radio appeared - one was for 2.4GHz second for 5GHz. Then one disappeared and there is only one again.
Basically this looks like nightmare, and I dont believe it is caued by adapter itself. I think there is settings issue + probably bug somewhere in the driver.
For me OpenWRT is horribly unintuitive and messy. Normally I would use documentation but it that is inaccurate and often outdated.
Unfortunatelly it is only available OS that theoretically has all features that I need.
I could use Ubuntu Server, but I think that configuring it would be even worse than OpenWRT.