Have a nice day.
Is flashing Asus merlin or openwrt an option? Not sure about the mesh nodes though. Hopefully someone else can chime in on this feasibility.
In all likelihood, you don’t need 6E and will be impressed by wifi 6. Consider GL.iNet routers such as the flint which are a built in router/access point. Then, you can set your ISP’s AIO (all-in-one) modem/router/AP into bridge mode so it just acts as a modem.
I got a chuckle out of that one.