Can the Adapter Box G3 control a water heater, heat pump, and EV Charger in the same system?

Yes. In the user manual provides a specific application scenario combining:

• Immersion water heater
• Heat pump
• EV Charger
• Solid-state power controller
• Load meter
• Inverter
• Grid meter
• Router
• Adapter Box G3

This demonstrates that the Adapter Box G3 can coordinate multiple controllable loads within an integrated PV energy-management system.