Aimesh alternative on Merlin firmware

[mrwxyz]

HI
I am having wifi stability issues on Asus RT-68U using Aimesh. One primary router and one node both running latest version of Asus stock firmware. Most often the client get disconnected and also often clients gets connected without internet access.
Quite a few times Aimesh node goes offline. As of now I have switched off the Aimesh node and things are stable. All I am trying to do is increasing Wifi coverage on the second floor.

Please advice the most efficient way to increase the wifi coverage with two Asus RT-68U using Merlin Firmware.

 

[Testscript]

This AP "UniFi nanoHD" is better than AiMesh:
https://unifi-nanohd.ubnt.com/


Try AP Demo "UniFi Controller software":
https://demo.ubnt.com/manage/site/outlets (Dashboard)
https://demo.ubnt.com/manage/site/outlets/settings/site (Settings)