we reinforce the coil cables as well as is possible. We have looked for (and paid quite a lot) to find other methods for coil reinforcement. But none of these turn out to be satisfactory (but they all cost a lot anyway). So far as I know, there is no tube, tape, or other thing that can be added to reinforce them further, or we would already have done so.
The coils can be made to be virtually indestructible, but they would weigh as much as a major appliance, cost as much, and be stiff as a telephone pole. If you take care not to pull too much or too often on the coils, we have basically reached a “design minima” for the cost, where the cost of replacement is less than the extended life adjusted for the cost of reinforcement.
The unfortunate fact is that anything you wear around in close proximity to your body will get a lot of wear and tear.
The best that can be done I think is to tape them up securely with a medical-grade cloth tape, being sure to secure enough of the length of the black vinyl cable to provide a strain relief. But this will not last forever.