As a quick follow-up on this. I decided to give it a go and stick with the original double-tapered design based on 5mm Robline Dinghy control. I have an undertramp takeup that works well and didn't want to risk the chance messing up the delicate balance.
Turns out my concerns on doing this myself were completely unfounded. This YouTube video was hugely helpful.
https://www.youtube.com/watch?v=7bWZpUQZO8E#t=190Hardest part was digging the effing core out of the plait. Had to borrow my wife's reading glasses just to see what the heck I was doing. I think it took all of a couple hours beginning to end. Next time would be half that.
Now its on to making a new set of dyneema trap lines...
