I didn't have to start over again. I flashed back the stock firmware since I had to return the device.
I actually bought the RT3200 for a relative. But due to it's short range and the complexity of OpenWrt (he is good with IT stuff but not with networking) he has decided to either go with Dynalink DL-WRX36 (AX3600 router (my recommendation, based on the advertised range and the fact that there might be a way to flash OpenWrt in the future Dynalink DL-WRX36 Askey RT5010W IPQ8072A technical discussion ) or a mesh wifi setup.