This is what Dynabar and Mystic use. Single braided Dyneema
This seems to wear very quickly.
This is what I'm more tempted to use - Double braided line
Donaghys Superspeed, or similar. This has an interior single braided line which is responsible for taking the load, and an outer braided cover that p;rotects the line

Here is a good article explaining the differences:
https://www.apsltd.com/aps-advisor/single-and-double-braid-sailboat-lines-explained/What I don't understand is why the bigger manufacturers of rope sliders use the single braided line, as it dosn't seem like the best solution. Am I missing something here?
The other thing is that Mystic, for example, don't offer any way to add a second rope, so you need to be fairly confident in the one thats there