I understand that a short amount of cord will not yield a significant weight difference. I also appreciate the idea that it's preferable the cord fails rather than the tarp.
I'm using a lot of cord. Maybe the weight difference isn't much, but it can't hurt to use the lightest material I can get. I have to carry it 2665+ miles! If you compare the Zpacks cord with the English Braids cord, the weight difference is double for 50' (~.5 to 1 oz respectively). If I'm using most of 50', it's a difference of 0.5oz. I know 14g isn't a lot, but again, if I'm going for the lightest, might as well use the lightest.
I know it sounds unusual, but assume I'm carrying 100' or more of this cord. The weight will add up.
I'm not worried about ripping the tarp. If that happens, I'll just have to effect a field repair. Thanks for the warning, but I'm confident in my design.
Maybe I will go with the braided fishing line. I'll have to go to Bass Pro shops or someplace and feel it. I'm just not convinced it will serve my needs.
Thanks again for all the suggestions. You guys have brought up some good points. Maybe I'm making the decision harder than it needs to be.