It sounds good! … If you want you can still use original asus firmware but it’s recommended to update it.
ASUSwrt Merlin is not realising 384 for my Asus AC66U it seems. I had problems with latest Merlin firmware devices not updating status over ssh. SO I reverted it to original firmware. Devices are now updating correct but not listing complete as written above Male because of something in Asus firmware. Waiting for an update of the component to read the new network list.
I have the same configuration and problem. Have you resolve it?