I finally broke down and bought an end feed shuttle, and it arrived yesterday along with 6 pirns. I was in LOVE with it after about a half dozen picks. Wow, what a difference! I usually have pretty good selvages since I use a temple and make sure the selvage is correct on each pick, but it is a slow process. This doubles the speed of my weaving and I don't have to do anything with the selvages but watch to make sure the thread didn't get caught on something causing a loop. I bought a Schacht and found it very easy to adjust with the little wrench that came with it. And feeding the yarn through is super easy too.
The only thing that's not easy, is un-weaving. I made a mistake and had to go back a few picks, and that wasn't easy due to having to hand wind the yarn back onto the pirn.
Wow, and when I think of all the time I've wasted over the years, weaving with a regular boat shuttle!