IM a fisherman, so i know a lot about line.
1. Stretch is NOT an issue on braided line. Hence the benefit of that line, you can fish 100 feet behind your boat and set the hook with no stretch. Monofilamant line stretches, and by the time the forces reach the hook to set it , the fish has already spit it. So it would have to be braid.
2. Braid has its own problems. Mainly slippage… So you would need to line the bobbin with rubber (im thinking a quick spray of plasti dip would work just fine). The braided line is very smooth and sort of waxy feeling, so it slips.
This actually seems more than feasible. If i get bored ill print a bobbin and give it a try.