Haha nice tool to have! I have often thought of doing the same. I have 3 old Dremels. A flexible shaft with a chuck would be awesome.
On the unsightly mast clumps, try using a #8 thread to tie up the stay rather than the much thicker stay thread. The thin #8 thread is barely visible and if you touch it with a bit of paint it disappears into the mast entirely. I get it on Amazon, fly tying Uni-Thread.
"Research is what I’m doing when I don’t know what I’m doing"
Wernher von Braun