AT&T Uverse "GigaPower" - Pace 5268AC - /29 Block

We have signed up for GigaPower commercial with a /29 "5-block", and AT&T has installed the ONT outside and a Pace 5268AC inside. We are being told that this is the only modem available for fiber, and it only supports a DMZPlus mode - which is not acceptable for our uses.

Has anyone had any success getting a non-NAT connection on GigaPower? We are willing to take the optical handoff directly if we could get appropriate specs. My first guess would be something like this.