I used a home made handle with an internal bellcrank kind of adjustment. no line clips, the lines were fed through a nylon eyelet and hooked over monoline button the adjuster. plus or minus 1/4 in. adjustment. It worked just fine with no wear ever on the lines.
i did try it on an F2D, but the lines, one or the other, fatigued from bending after 3-4 flights. Spectra lines have a nearly infinite fatigue limit.
As far as knots got, i talked to the district VP at Brodaks. The AMA tech committee is insisting on a better knot that the figure eight on a bight i've been peddling. They are proposing using the same knot, but after first doubling over the line and tying the knot with the doubled line, ending up with a doubled up loop that will always break the line in the middle , instead at the knot. A very good idea actually. Getting a full 100lb line strength on a combat plane is a very good thing with much less worry about a badly tied knot forcing an understrength break. The only downside is you'll need to get a small crochet hook to tie it easily.