A quick update. After about a month of smooth sailing, I was finally punted off the network last night. It appears that a required firmware update for the Pace modem was rolled out. After undoing the bridging setup and allowing the modem to communicate freely with AT&T’s infrastructure for about 30 minutes, it had updated. I was able to put the bypass back in place afterwards. I’m still working on a way to keep the pace on the network but inject my packets on the bridge.