Is there a way to tie that knot so that you end up with two lines the same length?
For 1/2a, loop it through the handle. Perfect every time ;-)
For larger....still working on it. I mark the lines along side each other with sharpie. I then tie the knot to include the mark...which sometimes works... as the knot is arranged. Then I tighten the knot.
Since the mark is included in the knot the length should be very close to each other, however this is a knot with a lot of turns AND it is a sliding type knot so arranging the knot usually moves it off the mark some.
For lead outs I tie a giant loop so the knot closes it. I can then pass the "bight" though the tip guide, the control horn, back through the tip guide, over the eyelet, and pull the eyelet to tighten the loop over the control horn to cinch tight. I tie up 3 lead outs and get 2 that match
so less than perfect even with care.
I have used these loops on a couple open-wing planes, and now 1 closed wing plane. The leads are pretty long out the wingtip, and it pulls more than line strength. In theory it should be about 2x line strength since it is doubled over all the way, but I haven't tested to failure.
Phil