I can empathize with the original poster. I owned an SM 69fet in the early 1970s and tried to use it for live concert recording. The cables just didn't seem to be made for that type of application; unrolling them and rolling them back up several times a week seemed to be too much for them, no matter how careful I tried to be. They spent nearly as much time in Gotham Audio's service department as they did in actual use, and I'm not exaggerating by much when I say that; I think I nearly drove poor Joe Leung crazy.
It wasn't a question of shielding and grounding, but of outright broken connections. I had to buy extra cables (each of which cost nearly as much as a good microphone) to serve as backups, bring them along to every recording (they're heavy!), and allow extra setup time, because I simply never knew whether they would work or not.
In a fixed installation I can see a role for this type of microphone, but not for the type of portable on-location recording that I've generally done, with a complete setup and teardown every time. By comparison the USM 69 isn't as flexible in terms of pattern selection--with the SM 69fet I often found myself preferring the "in-between" patterns that have no official names. But if you like the sound of this microphone design in general, and coincident stereo miking is what you need to do, it's a trade-off to consider, since four-conductor shielded cable is entirely manageable.
--best regards