When you say the "same issue" are you referring to the claimed evaporation, or pump rub?
Keeping an eye on the lube level solves that fluid level problem directly; it is the correct approach to proper maintenance.
Pump rub can only be confirmed via removal and dissassembly of the t-case. I supposed one might be able to distinguish it in a PC analysis. I doubt that a UOA would pick it up, because the resultant particles that come from the pump rub are likely to be larger than 5um, and that is the upper limit of spectral analysis; hence a UOA may very well not see the increase in wear elements. The real problem is that so very few people do UOA analysis on xfer case fluids, that there is probably no basis for "average" numbers for comparison. Typically the capacity of an xfer case is so small that it's way chepaer to OCI then to UOA. So, you come full circle to the "Do I have pump rub?" question; the only way to know FOR SURE is to take it apart and look. And if you're going to go to that extreme, then you might as well install the pre-emptive fix while you're in there.