Thanks again, stef. I think this thread is becoming the best how to make a foil kite presentation I have seen
To make dedicated presser foot for sewing the lines is very nice. I have managed with ordinary one, (I have some with grooves on bottom) but like you say it is tricky (almost impossible) work if line is thin. I've used quite a lot recycled lines from pg's and old kites, then at least one end is spliced/sewed. Other end is ok with knotted loop, especially if joined (by LCL) near canopy there is not much risk of tangles.
I strongly recommend LCL's, they make installing and servicing the bridle much easier. It is also possible to use them as an adjusters for single bridle lines, for example if wingtip area needs precise tuning.
It is best to splice/sew thicker lines of upper levels, knotted loops there are a bit too clumsy and catch other lines too easily.
PL TE is simplest possible, upper and lower skins are taped/glued together and then sewed through. No folds, just one straight stitch. No doubt folded TE is stronger, but is there any benefit of that, hard to say. If brakes are at TE, then folded TE is more needed if not obligatory. I don't think drag wise there is much difference, miniribs and/or narrow enough cell width is more important. Also how TE draining is designed has an effect on how flat TE will be. PL's mesh part is better than cut profile end, which causes small bulging there. But again, how essential this is, many race kites use cut ribs.