I also wired mine the same way and this way you do not have to turn off the battery charger of the converter... but it has nothing to do with the transfer switch.
The transfer switch is between the breaker and the rest of the circuit. If it has power from the converter/breaker it uses that to feed the circuit but if no power is received from the converter the Inverter can supply the power.
The disadvantage is that it only provides power to that circuit instead of the entire rv like plugging in the shore power cord would provide.