I think your concern about the Mutec cables is unfounded. I even have a 15m long Mutec cable running along the wall to the ADI-2 Pro in front of the HiFi. And I have had in the past years many of these cables for the different variants of my setup in use. I can assure you that there has never been a failure with these cables and that I could plug and unplug them several times.

Whereas with the Sommer Cables I was always afraid that through the stiff cables simply too high lateral traction forces act on the ADAT socket, that did not feel good for me, so I immediately took the Sommercables out of the rack again.

The Mutec cables can be easily inserted into a small plastic cable duct from the hardware store, which can be glued over the edge of the tile.

You can even twist several such cables slightly and stabilize them with cable holders every ~75cm, if you need several TOSLINK cables between RayDAT and other components in the rack. Then the cables are more stable, don't twist and are still flexible enough and then still very easy to plug and route in the rack.

I'd like to answer your question by saying that the connectors used on Mutec cables fit properly (not too tight, not too loose), and the connectors are such that you can use them even with somewhat closely spaced ADAT jack connectors without any problems.

The Sommercables are simply much too stiff due to their sheathing, very bad to "lay" in the rack and as noted, there are lateral pulling forces on the ADAT jacks on the device, I would recommend, not to use them. If you want a few Sommercables for free, I didn't throw them away, but I don't use them anymore ;-)

The cable does not need this thick sheathing anyway. Thanks to optical transmission / galvanic isolation, no thick shielding is required here anyway, which would justify this immobility / stiffness of the cable in any way.

You can of course do what you want .. but my "good meant" advice, give them back if you can due to online purchase ... Or just chalk it up to "lessons learned".