I realize it's been many years since I was in the military and training to be a ground radio repair technician and working with transmitters, receivers and wiring just like this cable wiring, and that I've been out of the loop for a long time on current advancements...
But back in my day you didn't have to pull wiring to know if a run of wiring was bad. You'd just take an analog multimeter and do things like ohms testing while also putting a signal through there to read amps and voltage and even frequency.
We even had caps to place on one end of a long wiring run so that you didn't need 500 yard long leads on your multimeter, it would create a feedback loop for various tests and you'd know in a few seconds if a long run of cable was bad and needing to be replaced.
Anyways, just trying to think of things that might can help y'all out.