I dont know about your wells, but mine are a place where the sun never shines. Thus the UV reduction of nylon or poly or black or white seems irrelevant. With thousands of plastics out there, we dont know the formula of the ties in any case. I do know the scotch #33 is American virgin plastic. Anything American made relating to virgins is okay in my book, And I dont mind tasting it in my water.
If one puts the wires in the "V" of the tie formed at the head, does not pull it tight with pliers, and uses tape too for vibration issues, I think its a good mix.
I dont think the asian tapes made from the ground up back seats of old Buicks and Ramblers [where the American girls ceased to be virgins] and water buffalo hoove-hide glue is the best choice.
Just my small and of course un-biased opinion.
I have sketched a fabrication system for years for well drop pipes, where one would put the pipe on a [long!] rotating jig and build a custom pipe- wire- standoff assembly in a few minutes to order that would beat anything made in the dirt and dog dung of the average yard.
Send me a royalty when it happens.
Which reminds me. 20 years ago woodworkworkers supply had a best new product contest, grand prize 30$ I submitted my sketch of the collet type quick change drill bits and drivers. I won.... I got 30 bucks. Now every tool box has my idea in it - they marketed it and resold it a hundred times.