Hey Duke,
The pigtails are really a bit of a left over from the days of 2-lines. They used to be there to change the set pitch or angle of attack of a kite before you launch. However, in this day and age, most standard bar setups have approximately 10-12 inches of travel on the centre line or chicken loop line and a further 6-8 inches of travel from the trim strap.
This is of course way more than you will ever need as most kites go from full power to slack back lines with around 12-14 inches of depower. Having used that theory the trim strap is then superfluous or the additional length of depower rope is superfluous. I mean what good is having so much depower that you cannot steer the kite when the bar is depowered?
You can however take advantage of this massive depower range to modify your bar setup to make your posture more advantageous ie remove the amount of depower so you don't have to lean forward to reach the bar when depowered, (this removes the poo-hanger stance)then utilise the full travel of trim strap adjustment.
You need to start off with the 4 flying lines on your bar at equal length when the bar is three inches from the chicken loop stop, this gives you around three inches of oversheeting which can be advantageous in jumps etc. The knots on the pigtails can be used as a quick adjustment at the beach if for some reason the bar is not even when you first launch without having to go to the trouble of rerigging and adjusting all your lines.
I teach much of this stuff and more in the intermediates riding clinics. Hope it was of some use.
Good winds
