@Zoomschwortz just blindly dumping the engine oil with a change isn't going to help answer any questions you posed. You should take at least one oil sample that has over 1000 miles on the oil to look for major problems like coolant or diesel fuel in the oil. Likely you will just waste your money for a good sample. However the times you get a warning from an oil sample you can possibly fix a problem before you rebuild an engine. An engine oil sample isn't that expensive in context of the oil cost that was just changed. I use a "vampire" kit and take samples from the dipstick tube so I don't have to change the oil for a sample.
Point of fact the PO of my 2003 5.9, old guy pulling an RV like yours was, had blown up the engine so badly that coolant showed up in the Manual Transmission oil sample result.

Yeah I sample more than just the engine. I also cut used engine oil filters open to check for "part numbers" metal debris, dirt, sludge, and to see if the filter held up as some were missing a pleat crimp, had torn media, and at times a t-shirt stuffed in a can would have "not" done the same job just as well as a defective filter...
You killed the grid heater over battery drain concerns? Are you short tripping a diesel engine? Otherwise it runs long enough to charge the batteries back up... IMO you should hook the grid heater back up over the white smoke concern. If short trips apply at all install an automatic battery charger and plug it in once a week to top off the batteries. No it isn't absolutely needed, but, it helps reduce smoke from unburned diesel. Oil washing from unburned diesel on the cylinder walls from cold starts is a long debate you can read about. The colder the engine and air the more diesel that doesn't evaporate and burn. Again advantage for grid heater here...
I would keep a sharp eye on the coolant level and check all the injector lines,
engine off!!!, for leaks. Engine off because a high pressure injection system leak can cut your hand and with hydrocarbon poising you will loose the hand.
My 2003 had a road draft tube so the engine oil smell would get into the cab. There is a long thread somewhere on sealing up the missing drain flapper and the rest of the cowl/firewall area where the HVAC takes in fresh air.