I asked the same question to Givenergy chat. This is what they said but I don't have the kit to test it. Conversation below - let me know if it works!
I have a Hypervolt car charger, that has a CT clamp and a setting in the app to only charge when the PV is generating surplus electricity. I have also looked at iboost to divert surplus generation to power an immersion heater.
Can I set this up in some sort of priority order so that the car charger, iboost and AC-coupled aren't all fighting each other for the same power?
you'd have to check with your manufacturer of the charger on that one - some can yes
our battery charges at 100W excess
to setup priority, you would set the car to be 200W for instance
that way battery would always pick up first
or if you wanted hot water to be first in priority, you'd set it to be 50W
so then it would go hot water > battery > charger
MyEnergi can do that, not sure about hypervolt