Phoenix 24/1200 ground query

Hi, I am in the process of installing a much larger 24v 280ah battery to my Campervan system.
I have PV with 75/15, Blue smart Mains charger 24-24-16, Orion tr smart DC DC 24-24-17 isolated, I also have an Orion 24-12 convertor for distribution.
At present I have no ground connection to chassis on all above.

For very occasional use I have a hookup/shore power connection point connected to 1 RCD protected twin socket. Earth terminal from socket is connected to a separate chassis ground/earth.

I am adding a phoenix 24/1200. Plan is to have another separate rcd protected socket plugged into socket on the phoenix. From reading manual, I think I will need to change phoenix from floating neutral to neutral connected to chassis and connect phoenix earth point to chassis at same point as my hookup earth point on chassis
I hope I have explained clearly, I am just after clarification to my plan for correct earth/ grounding
Many thanks.