Thanks for the detailed answer - very helpful.
Since the premade top stops are so cheap and easy, I will just use those for the top stop, anytime I need to shorten a zipper (1-way separating or non-separating).
However, as an alternate, I really like your idea of hand-sewing thread around each half of the coil. Seems like that would work very well too.
For bottom stops, I did some experimenting last night and by going slowly and sometimes by hand, I was able to sew right over the zipper (#5 coil). That created a pretty nice barrier. I did break one of my #10 needles going too fast, but I switched to a #14 needle and that, along with going very slowly, seemed to let me stitch lines across the zipper tape and zipper, creating a stop.
However, here too, I guess I see no reason not to use the premade stops for bottoms too (for non-separating zipper use).
Regarding the premade stops, any preference between the pronged type and the “C-shaped” types? Is one for coil and the other for Vislon (toothed) zippers?
And regarding the wedge, still not 100% on the construction… How much zipper tape do you need to leave past the end of the zipper (where the stops are)? Seems like you need at least a 1/2” or so to have enough fabric to sew the wedge on to.
Zipper | 1/2” Overlap | Fabric
And could that wedge fabric also double as a stop?