What I do to cure the problem of the center portion of the feather not sticking is this. (Maybe it'll speed things up and save you some time, Christine.

)
I put the feather in the clamp, then run my thumbnail between the edge of the clamp and base of the feather, wedging it out of the clamp slightly, so the feather is sticking out just a bit. After putting the tape on the feather and stripping the backing off, I put the clamp in the jig. While in the jig, Ipress my thumbnail on the wide edge of the base, right against thebarbs,and run it downto the other end of the quill, making sure the feather is stuck down all the way along. Then I remove the clamp and press my finger down firmly on the leading end of the feather and run it all the way to the back end, making extra sure it's stuck down.
Index to the next position and repeat.
With left wing feathers, you can't get to the wide edge of the quill, so you have to skip that step. But I'd still press the whole feather down after taking off the clamp.