Even with the battery disconnected there is still going to be a draw from the converter to power 12v appliances/devices. If you completely turn off the converter, your 12v appliances/devices will run off the battery and you will have full generator power available for your high draw 120v appliances. Most of those high draw appliances only need the extra power during start-up, so PrivatePilots method of putting in a switch to turn off the converter would allow you to turn it off during the startup period, and then turn the converter back on.
If you wanted to get really fancy, you could add an extra relay to the A/C thermostat circuit that would cut power to the converter whenever it decided to turn the A/C on. With some cool electrical engineering you could make the relay only kick off for a minute to allow the A/C to finish starting up. Doing an automatic cut-out for the Microwave would require some EE skill as well.
