Victron EV Charger in auto mode in a Victron Microgrid system

Just wondering about the scenario where I have a Victron Microgrid made up of say two systems that each have a MultiPlus II 5kVA, battery, PV and a GX device.

I then install a Victron EV charger which talks to GX device 1, since there are no comms between each system in the local microgrid, how can the EV charger know that it can now use 7.3kW of single phase power in auto mode when both systems are contributing?

Perhaps a solution could be that the EV charger software is updated to allow talk to multiple GX devices at once so that it can then work out the total PV power available?