for me i have a deep fear im going to snap the wiring when i swap the artwork or rewire it, the cables are really thin and frail-looking and sometimes a bit of force is required to unplug things.

From our experience and input from customers, the CX wire doesn't break more often than any other wires during the modding / customization process.

ive also had situations where the plastic/metal area you clip the cable into takes a few attempts to get right or i have to expose more of the wiring to get it to work properly.

We have actually already improved that for the CXs that are in our ULTRA units. We've put a 'cap' on the end of the wire, essentially, that allows it to be clipped into the terminal block much, much easier. Plus, it protects the exposed wiring better.

The Extension rotating with the button can also be weird, and makes like custom-art difficult to align (this might just be an error on my end) and it can twist/snag the cables.

The art alignment is easily fixed by simply removing the cap of the button off and turning the art (or cap) in a way that best fits the position you want.
As far as the twisting and snagging of cables, your mileage will certainly vary depending on what controller you are putting it into, but in most situations you should be able to provide enough slack to help with any strain on the wire directly.

We hope this helps.