Initially because I no longer trust Shure cables. And so that I have an extra for emergencies as I travel a lot. If only for that reason, £90 seems a bit much.
The Linum G2 BaX cable I had (which is about about £100), in my mind anyway, made my 846s sound miles better than they ever had before, but I don't know if that was a placebo. I had some downtime between the Shure cable and finally getting the BaX, so I was never able to do a direct comparison.
So I guess for £90 I would expect similar improvements. I'd go for the BaX again if the build quality was better, the plastic covering of the cable is so thin, it started to split inside 2 months and I had lots of exposed cable everywhere.
FWIW I had similar issues with a couple of bax cables on ciems that were all the rage at the time. One had the cable split that you mention and the other had jack issues. Nice and light, but tangled like mad.
I was curious and had a look at the Linum webside for the mentioned Linum G2 BaX cable.
Up to now i did not know this or the brand.
Linum declared this cable suitable for > 10 Ohms earphones, the SE846 has 9 Ohm.
I know this is not a hard rule, but when you follow Linums product philosophy, they
recommend the Linum G2 SuperBaX cable to be paired with the SE846:
"For <10 ohms and multi-driver earphones, we recommend the SuperBaX"
The prices aren't cheap (they are Danish, ok), starting with
~100 EUR for the mentioned unbalanced Linum G2 BaX cable,
~250 EUR for the unbalanced SuperBaX G2 and up to
~311 EUR for the balanced SuperBaX G2 cable.
Further more, there is currently no 4.4mm TRRRS available, only a 2.5mm TRRS.
I have to admit, at this price level i expect also a good durability, when i read your experiences that it is very sensitive, i stay with the Fiio.