If your batteries have a compatible BMS, which they should, than you do not need the shunt.
Watch Andy’s Offgrid Garage on YouTube.
For battery protection, you can use Lynx for Mega fuses and use Adler EF3 fuses capable to clear 50kA.
You need DC-Switches to disconnect MP2 and batteries from Lynx.
If you want to connect/disconnect from grid frequently, consider an external relay.
You can add solar by AC-coupling (best fronius) and DC-coupling (Victron MPPT and RS).
