Your coach is an Aspire so you probably have half the battery bank of an Anthem or Cornerstone, but you should have no trouble while traveling. You should have a 125 to 200 amp alternator in your coach that is more than able to supply any of the 12 volts that you need for the coach while traveling. Some of that amperage is going into the Magnum inverters which is supplying 120 VAC to your refrigerators and the motor alternator alone will easily supply all the voltage your inverters need to power all the basic appliances in your coach while traveling.
The only time that you need to have the generator running while traveling is probably if you were in any of the southern states during the hot summer months and your dash AC cannot keep up with the heat and you want to run the roof AC units while traveling.... The Cummins engine alternator is not able to handle the loads of three AC units, and if you want all three of them running or even two, you would want to consider running your genny to deal with their high need for amperage/power.
If you are traveling 80% of the day moving down the road, you should not even need to worry about running the microwave plus the refrigerator and any other odd 120 volt appliance for short periods of time (maybe a half hour or less of microwave use) even with the engine is not running and if you leave the Cummins running, it is supplying lots of amps while you eat lunch. After a long day of travel, you should be able to run the genny a few hours before you go to bed at night if you might be boondocking in a WalMart type place, let the refer run all night, and should be OK. Of course, set your AGS (automatic Generator Start) to start at 12.1 volts and let it run for 2 hours (its normal run time on AGS) and you should easily make it through the night. I then run my genny in the morning for ~ 2 hours to recharge the battery power consumed over night (and that is even while running down the road).
Your BIM switch will always take care of your house battery bank recharging first before it worries about your engine start batteries. If your chassis (engine start) batteries are above 12.6, then the BIM will default to recharging your house batteries.... Every hour or two it will go back to check on the chassis batteries and if they are still in good shape, then the BIM will go back to charging house batteries. But if boondocking over night has heavily discharged my batteries, I will run the generator for an hour or so while traveling as the generator will put a much higher current to the Magnums to recharge the house bank more quickly.
We do this all the time. Now, we probably have twice the batteries in our coach that you do in the Aspire, but you should still have no trouble if you set the AGS to >= 12.1 volts before going to bed (while boondocking).
Gary and Dee, Zowie and Bowie (traveling cat sibs)
2019 Cornerstone 45B, X15-605hp, Imperial, Spartan K3,
2013 Honda CR-V toad, Demco Excali-Bar II,
Demco Baseplate, Demco Toad Light system, 73 de W5FI