Got the UCG-Fiber successfully working with Swisscom 10 Gig Internet two weeks ago behind a Zyxel PM7300. Fiber into the PM7300, copper to the 10 Gbe copper WAN port on the UCG-Fiber.
I was considering trying that, and had found some promising reddit threads. When I received the AX7501, I realized the optic is designed in a non-removable way, so I didn't bother to try yet. The set-up is currently working quite okay with the UCG-Fiber behind the AX7501 (in DMZ mode).
