Question about ASUS Rt-Ac66u

I have been using Asuswrt-Merlin for years. From my point of view, it's easy to install, super stable and very easy to use via the web interface. Therefore, yes, it should work. Here is a link to a detailed manual:
https://vpn-anbieter-vergleich-test.de/anleitung-...

The router supports openVPN with standard firmware (also PPTP, but I have not tried this).
Since it was not quite stable, I have installed the DD-WRT firmware. also comes with openVPN. Other protocols are also available.
Installation was not trivial (not all releases work), but after a few hours it worked. Firmware: DD-WRT v3.0-r42335 std (02/10/20). Important is -> every now and then the connection is gone and you have to initialise it again from the web console. In my opinion, it is not yet suitable for living room, and rather for IT oriented people. Maybe it depends on the VPN provider.... mine is purexxx. Not recommended...
But the router will work with express as well as nord, with or without dd-wrt.
I hope this helps you.
Best regards,
Pawel

I haven't had the device for a long time and therefore can't answer your answer.