Transfer cases in question both owned by me since new. Both get 30 K OCI. Both using Matic D, a dex3 Based fluid according to this website, worked fine for a decade plus. Changing from Matic D to Max life caused shifting difficulties in both, and almost immediately. Switching back to a Transmax dex3 based product reversed the issues almost immediately in both cases.The fluid change by itself is likely what made the difference. Unless you're using a high-grade, synthetic "Dex3" I can't imagine there would be any significant, fictional difference between a Dex6 / Dex3 / Maxlife fluid.
Changing the fluid before wear / contamination increases is always a good idea.
Possibly it has nothing to do with viscosity, but it also has nothing to do with wear. Simple solution in my case, I poured the remaining Transmax into the recycle container at my recycling center. Problem solved.
In my very specific instances, this product did not work in an application for which the specifications seem to imply it should. Both cases continue to function as they should with different fluid. One is almost at 30 K again with no issues, and I’ll change it out shortly using a dex3 type product.