AXT1800 Firmware 4.5 Rollback to mwan?

Hi,

I was using the ip rules feature of mwan to dispatch the packets to the right wan in a 2-wan setting, and also using the luci UI for mwan for convenience. After I upgrade the firmware to 4.5, suddenly those are gone and no equivalent options exist in kmwan and the official Multi-WAN UI. And I assume kmwan and the original mwan cannot co-exist?

So, I wonder if I may rollback to use the original mwan instead of the kmwan? If so, how to do this properly?

Thanks.

Maybe just flash back the old firmware.