But the way, I think I discovered a bug with this experimenting.
Have a look:
https://forum.openwrt.org/t/openwrt-19-07-2-service-release/57066/16?u=lede_dude
Scanning of 5GHz networks does not work under certain country codes.
root@OpenWrt:~# iw dev wlan1 scan
command failed: Resource busy (-16)