The Momentum cable is thinner and it's around 2mm thick including insulation. If the insulation is same thickness (around 0.5mm), then wires are most likely around 0.2-0.3mm, which is on the boundary of what 18 Ohm Momentum need from 1.5 meter cable.
Anyway there is other problem. The cable maybe is reliable in sense that it still plays stereo, but because it's 3 wires twisted tightly together in a single insulation following problems arise:
- crosstalk, which will rather significantly (depending on what is for you significant) decrease soundstage, and
- possibility of short circuits, and thus changed resistance between left and right that will affect middle point
The first problem is less of an issue, but second unfortunately is something you'd rather avoid.
A twisted pair that I have mentioned has this advantage, that every single wire has it's own insulation, and then there is second advantage if you make two twisted pairs, then each channel will be ground twisted with signal wire, and this will reduce electromagnetic influence between left and right. Note that if you have two signal wires very close to each other (only thin layer of paint is a distance) there will be very strong electromagnetic interaction. The article you mentioned does not mention that, because in that article they look at loudspeakers cables, and it is obvious there, that left and right speaker have separate signal-ground pairs in two separate cables. With headphones there is a problem, because both channels are usually transported in the same "cable". So best would be to have two separate twisted pair cables, which I am going to prepare, and see how good that is (Already bought all that is needed).