Thanks to the huge thread I finally got my Xiaomi 4A Gig with OpenWRT, AWESOME.
I was using the router as "repeater bridge" I thing this is the exact term, as it is not WDS, wireless access point or simply repeater.
With the Xiaomi firmware it was connected to the main router using 5Ghz and creating 2 networks, one in 5Ghz and another in 2.4Ghz. For the clients it was totally transparent, Main and repeater use the same SSID, same subnet IPs, just a bit of roaming when switching between the two routers.
Well, I cannot reproduce the same configuration with OpenWRT. May it be not supported? May it require the proprietary driver?
Thanks a lot.