The ideal steering line length varies from one model of canopy to the next. PD says to tie the steering toggle on at the factory marks. The problem is that the guy who designed them has arms way longer than most. When I relined my Sabre, I tied the toggles on at the factory marks, but this resulted in a lot of slack in the steering lines which required large arm movements to turn, and I could not stall the canopy. Over the course of a dozen jumps, I gradually shortened the lines by six inches. This took the slack out of the steering lines, improved responsiveness and it still turf surfed much farther than with the old lines. One caution, if you shorten the steering lines much more than six inches, your landings will suffer, because you will fly final approach in what amounts to quarter brakes.
Yeah brakes are different etc. My friend Derek lengthened the brake lines on his custom VX60 6 " past factory (yes he is... extreme as it were) so that during his dives, the drag on his brake lines (at 80 mph) would not distort his airfoil as much and therefore give him a longer faster dive (he wants speed not swoop length). Well that is his theory anyway.
I was really enquiring as to any one re-trimming their canopy other than steering lines or what in general is the line trim practice of those extreme canopy pilots that are flying at 2.2 loading and up.
First of all, like the first response says, my brake lines are VERY loose. I can pull both dive loops all the way down to my chest with my toggles in my hands and not deflect the tail at all. If you can't do that, then you are just asking for your main to buck or "porpoise" in your one-riser dive. My wife's Stiletto 120 is set up very tight and I absolutely hate it. Any front riser input at all makes it buck wildly.
As for the other line-length mods I am referring to, some guys are lengthening their lines at about 1/2 inch per lineset from the inside out. This, to REALLY flatten out the canopy over your head. I have not done it, but have seen mains done this way and their owners swear by it. One guy, a Stiletto driver, said his openings were slightly harder, but more on-heading. That, and his surfs were MUCH longer as compared to stock trim. In another thread (concerning Slinks) I wrote about guys fine-tuning their front to rear trim by putting Slinks on one end and Rapides on the other (front or rear, obviously). Joe Trinko taught me that one.