A kink sleeve (almost) fits

This buckling cases are worth every penny by the competitive price for private use.
Have now installed almost half and can confirm that the seat to the cable is a little loose and the bulge of the plastic clip of the plug is a little difficult, but super from a processing perspective.

Have for laying CAT 5e FTP cable taken, so may well be that with some higher quality cable and extra shield also increases the thickness of the cable and the connector so that fits better. However, I attach such cables rather in fixed installations with corresponding network sockets and not with crimped connectors.