HI there,
Just a fact about 700r4. Remember that Reeves Callaway use these, unmodified, in the Supernaturals, and the Twin turbos, with hardly a hiccup.
Supers were about 460 ft lbs of torque, and Turbos were upwards of 600 ft lbs of torque.
Personally, as long as the shift points are quick and concise, and there is not a sliding shift, you should be fine with any issues.
Personally, as long as the trans is maintained, like a cooler, correct changes of the fluids, and the like, I have not seen one fail.
Best to all, c4c5