e60deluxeB
look up surface mount keystone box. thats the best you are gonna be able to do.
when you have to sign in with an ID password, it means that your company is using WPA2 or WPA3 Enterprise. There is an authentication server that processes your credentials and grants access to network resources based on the network access control policy.
It is not possible to answer your question without knowing the details of the network access control policy.
what model is your access point? is it the Asus? is it in Access point mode?
you should be fine on that router.
you dont need 6E, most likely. Get the EAP670.
(that being said, you probably dont need 2.5Gbe either)
almost certainly your router and adguard installation only respond to web management on their own subnet.
Get a router that can actually do a PPOE Passthrough without NAT, such as a mikrotik.
may be a bit difficult to configure though.
DMZ on home routers is basically a 1:1 NAT with no firewall. so DMZ working correctly will still NAT.
if the issues are isolated to physical areas, the internet package isnt the problem.
so in that cases, mesh routers may be an option that works.
dont set any PVID, or leave it on 1.