Need Replacement: Vinyl Awning Rope, Keder Rope, or a third option?

Tablet

Best option for replacing awning rope: Vinyl, Keder, or is there a rubber version? I have an awning that I need to replace the roping on that goes in the track. For some reason the roping on it (although it was made for a Tab) is .255" thick, and it comes out of the track very easily. My Thermarest tent has what seems like rubber roping that is about .3" and works well. Sailrite suggests I use Keder, which I have never seen, and I'm guessing that what is on the Thermarest is not vinyl as it seems too soft and flexible, but maybe it is vinyl and not some kind of rubber? Any advice please?

Tampakayaker

I ordered this from Amazon when my wife made our visor.
It has the flap built in that you sew onto whatever your making/repairing.

Keder - 8.5mm (5/16") Welded Flap, Standard, Black - 15 Feet