any slush box mechs out there?

[AKMark]

Putting the T-case in neutral while flat towing doesn't lubricate the bearings. I would pull the rear driveline, as flat towing for very long wouldn't be good to your T-case.

I would run a gauge on the pressure line going to your cooler to give you an idea of how hot yours is getting. (An additional cooler cannot hurt) If you downshift once in awhile, it won't do much, but do it a lot and you can plan on rebuilding your trans earlier than others do.