I'm not sure about custom, but adding a sleeve to your cable would be very simple using some cable sleeving from amazon like this and a small bit of heat shrink.

https://www.amazon.com/Expandable-Sleeving-Flexo-Sleeve-Silver/dp/B07NZLR8HS/ref=sr_1_16?dchild=1&keywords=1%2F2in%2BPET%2Bsleeve&qid=1622761065&sr=8-16&th=1