RE: Shrink fletch
I tried a package of them several months ago. At the time I was using 2315 aluminum arrows: they went on well and seemed to shoot well. The vanes became wavy from the "shrink" process, but that did not seem to cause any problem for shooting.
However, after about 35-40 shots through my Whisker Biscuit, the vanes started tearing off. For this reason I would not use them again.