first, the EMC XLR is cool, but probably overkill in this arena. offstage environment is much less RF rich than onstage/sidestage what with all the wireless stuff going on these days. not to poo-poo it, the cost up is probably minimal and does provide extra insurance and it just might be very well worth it.
however, i bet that the people most likely to experience RF issues are those folks running something like the MK46 system. as correctly said by Freelunch, the signal travelling down the MK46 is unbalanced, something no good FOH or monitor engineer or recording engineer likes to see. at to that the fact that the signal, despite the FET boost, is still pretty small in magnitude. when you add in the non-optimum shielding provided by the original cable and add to that the possibility that some of that shielding may be compromised - read broken strands - then one can see why the umbilical system is more suseptible to interference. my 2 cents anyway.
one of the issues with replacement cable is the very low capacitance of the original cable. increased capacitance and long runs can work just like a low cut filter - something we all want to avoid. resistance is also an issue when replacing this application's cable. i looked long and hard when i searched for a more durable cable when i did the original replacement on my MK46's. i think i will look into other styles of cable during the course of this project. HOWEVER i believe the triaxial design is the best for this project as my current understanding extends. i think we just may have to accept the wear and tear issue here and plan for periodic cable replacement. this might give a push to the lemo terminated cable and adapters for the caps and bodies as previously proposed, but i do not believe any product i build will be assembled in a way that would preclude an end user w/ decent soldering skills from repairing their own cables. i have no desire to build something so proprietary that only i can fix it.
i know that many of you tape more than i do, maybe MUCH more these days, but i typically build all new XLR cables every two years. most sound companies do the same even tho the cable(s) may or may not exhibit any problems.... everything has a finite life and they cannot chance failures. how many of you do the same? so, from the industry standpoint, they would already have replacement schedules drawn up for the MK46's.
also, i believe the original purpose of the MK46 system was for permanent install situations like stage or orchestral with the benefit of the smaller profile of the CKxX caps only visible. in that scenario, the cables would likely remain "undisturbed" as compared to our setup/teardown, etc, etc and the possible wear issues we are discussing might never surface for users like that.
anyway, i will query a cable manufacturer at some point for the real engineering answers on the triax cable/shielding/durability/etc issues.
neil