What is the best way to keep these things in sync as much as possible?
Use utility meters that you can calibrate (must have tariffs).
I have an emporia vue and enphase solar system… where the emporia monitors the whole house and the enphase monitors the solar production and consumption… the reason I added the emporia is that I didn’t want the hot tub to be backed up by batteries so it’s outside the “view” of the consumption CT’s. Just trying to sync it up with my power bill as close as I can.