AC Break Panel Mods for Dual Main Breakers

[Casa_Woody]

A few months ago I had a 600W solar system and a 3000W inverter installed with 4 BB 100Ah batteries.
The inverter is a Victron MultiPlus-II 2x120V Inverter/Charger. This inverter has an AC OUT 1 and an AC OUT 2. OUT 1 provides AC power whenever connected to shore power or when inverting. OUT 2 is only active while on shore power. The idea is to connect loads that you don’t want on inverter power to OUT2, i.e. the air conditioning units, thus saving your battery power for the essential loads such as the refrigerator and TV.



In my current setup I am not using OUT 2, all loads connected to OUT 1. I’ve come up with a what I believe to be a very clean way of splitting my AC power panel into two segment.

The power panel is a Progressive Dynamics PD55K000 (1 main breaker with 8 slots (16 circuits). PD shows an alternate configuration called the PD55K005 (2 main breakers with 6 slots (12 circuits). See below pictures.



My plan is to use a Dermal tool to cut out a small section of each bus bar so that my panel is configured the same as the PD55K005. I will then run 8ga 4conductor cable from the inverter to the second main breaker and reconfigure the breaker layout per the below diagram.
The current main breaker is a 50A.



Pros:
- All breakers remain easily accessible from the camper interior, in the original location
- Removes the AC units and fireplace from the inverter OUT1 load bank
- Minimal cost: a few breakers and some 8ga wire
- Level loading across L1 and L2

Cons:
- May require a new breaker panel is I muck it up

Any feedback on main breaker sizing? Cable size? Load balancing?
Any thoughts on my plan welcomed.