I have a friend who has Zen FTTP on a Dream Machine. I can't get IPv6 working (unsure if it's an account thing) but other than that he gets full 900Mbps.
I have a UDM Pro Max, prior to that a Cloud Gateway Ultra. Both were/are fine. 911 down and 111 up on the 900 package over openreach and a non-zen local exchange.
I guess it would have been more helpful to specify the type of feedback you're after. Zen FTTP works on Unifi, but I can't imagine that's the feedback you need.