Adding extra info the the Cerbo GX ( from SmartShunt power meter and Shelly EM)?

The background:
My Victron system is in a small travel trailer. I live full time in the travel trailer and try to stay off the grid as much as possible. While I LOVE the dual MultiPlus 3000 because I can run anything and everything I need, for 95% of my needs the overhead is too high for running the light day-in/day-out A/C loads I need all day long: computers, monitors, Starlink, CPAP machines, and other small devices.

The project:
Use the Pheonix 800VA inverter I already own. Before the Victron install there where some outlets configured for an inverter. Install the Pheonix to run those outlets when the dual MultiPlus II are not running. Since the Cerbo GX can only show one inverter group (the dual MultiPlus II), my idea is to install a SmartShunt as a DC meter on the DC side of the Pheonix 800VA and the Shelly EM + 50A Clamp for the AC side.

The problem: How to configure the Cerbo-GX to display this new info as a separate little box that will show both DC usage and AC output.