Yeah - manual/manual xfer case is best.   That way you really *could* just drop the rear shaft and run FWD only for a while.  Just don't drop out of 2WD high... That would be a mighty big "neutral" gear all of a sudden.

Optimal would be dual-range xfer and manual, with dual sticks, of course, but even the stock manual gearing is plenty fine off-road.(and your resale value will bump up a bit as well with a manual MC trans/xfer combo)

I mention it because replacing the automatic or rebuilding it will likely cost as much as just replacing the thing with a manual and a good used set of components.   While I'd def use a used and good condition (hopefully MC of course) manual as a swap-in, no way with any used slushbox.  BT,DT, never had a used automatic ever last more than a year.