On the subject of grounding. Victron has this statement on their MPPT FAQ page.
www.victronenergy.com
I agree with the reasoning behind connecting DC negative to chassis ground at a single point. Avoiding ground currents (ground loops?) makes sense. You don't want return currents to take multiple paths.
The question that immediately came to mind for me when I read this is what about alternator charging where the alternator negative is connected to chassis ground near the motor? In that case, the only ways to not break this rule is to either use the alternator chassis ground connection for the system negative chassis ground connection (and don't ground the house battery negative terminal) or use an isolated Orion TR with the negative out connected to the battery which is then connected to chassis ground. Either scheme should work the same.
My opinion is that DC systems should be completely isolated from vehicle (chassis) ground except at a single point where the system negative is connected to chassis ground. In my further opinion, the best power and ground distribution scheme is a star where every DC load has a dedicated positive and negative wire that feeds back to a central positive and negative bus bar. The battery is connected to the positive and negative bus bars with dedicated wires. In this case the negative bus bar is what should be connected to chassis ground.
Further more, these paired positive and negative wires should be kept in close intimate contact with each other as much as possible. I would either route wires in a conduit, use a jacketed cable or a twisted pair of conductors. What this also means is you really should not have several loads sharing a single negative return wire. Or use a single positive supply to multiple loads with the negative current for each load being returned in individual wires. Don't cheap out and try to get by with fewer wires. NO DAISY CHAIN WIRING, POSITIVE OR NEGATIVE!
This is good practice both from a signal integrity standpoint and also for RFI/EMI both for radiated noise plus susceptibility to induced noise. In the case of power wiring, signal integrity is not important, but the noise issue could be a big deal, especially for AC inverters and DC-DC converters (both MPPT Solar Chargers and alternator chargers) which can create interference in things like Radios and TVs.
The same concern also applies to your AC wiring. Again, no daisy chain wiring. Each outlet or load gets it's own dedicated hot, neutral and ground wire that comes back to a center distribution point. And the ground bus is connected to chassis ground at a single point (ideally where AC power is generated (inverter) or by the external neutral/ground bond when connected to shore power.