That little roller gizzie is the absolute bomb. First I have heard of it. Neat stuff. Maybe a little overkill, but hey, its a hobby . . .
i have broken a throttle cable and replaced it by the side of the road with a spare in about 20 mins. Mention of lithium grease from time to time is good advice. They make a solid pin that fastens to the braided cable end that then is captured by the swivel on the hex bar arm. This does lessen considerably the repeated over-flexure of the braided cable. The cool little roller shown here is a much better idea. I love it.
Heim joints on the hex bar pivots: clearly the right idea. @Gordon Nichols has provided a little parts bag and instructions on how to do that for a nominal fee. You do have to cut some metal and drill two holes, but it's aluminum and not too hard. And is a world of difference. That sloppy std hex bar pivot thing is terrible. IMHO. Someone here could post a picture of how that works, I'm sure.