It may not help for you if you need some advanced features from Merlin.
I got a Fritzbox 7590 (modemrouter) from provider, so I use previous 7582 as mesh node and going to buy one more 7590 (or cheap 7530 or 1750E-repeater) in mesh too.
This 7590 got no AX, but 160MHz bandwith in AC-mode perfect for my Intel AC9650 and doulbing speed (compared to 80MHz).
Mesh ist JUST RUNNING SMOOTH!!!
Guest-WiFi supported on nodes.
NAS on router (USB-HDD) without troubles (not usable on Asus).
Secured DDNS access to router and intranet from outside well done too.
Everything just running fine without faults, thats what I want to have, no hassle anymore!
All the basic stuff I need is runing like advertised, exatly what I want to.
Its time for me to say goodbye to all in this forum ...