My installation on my last bus more closely followed your first transfer switch configuration.
That gave me the ability to "automatically" disconnect high current loads when I was running on invert power.
Not sure if I can describe this properly,.....
I ran shore and generator into the transfer switch. The load side of the transfer switch went to the load center mains. Then I wired branch circuits for all of the high current loads and one branch circuit to the inverter input (ATS built in) and the inverter output went to a sub panel for connection to inverter powered branch circuits.
In use, it auto switched between generator and shore power. When one of those two was available then all branch circuits are powered from shore/generator. In the absence of shore/generator power the ATS in the inverter will power up the inverter backed circuits and the non-inverter backed circuits are dead.
I hope that makes sense