Regarding jump putts and stance:
A few weeks ago I heard a relatively experienced golfer explain the advantage to a jump putt as being able to release the disc in the air, as you're moving forward. They said they were told this by an even more experienced golfer. If I hadn't heard this, I wouldn't have thought this reminder would be necessary.
Here is the rule regarding stance outside 30 meters (jump putt range)...
803.04 Stance, Subsequent to Teeing Off
A. When the disc is released, a player must:
(1) Have at least one supporting point that is in contact with the playing surface on the line of play and within 30 centimeters directly behind the marker disc (except as specified in 803.04 E); and,
(2) have no supporting point contact with the marker disc or any object closer to the hole than the rear edge of the marker disc; and,
(3) have all of his or her supporting points in-bounds.
B. Stepping past the marker disc is permitted after the disc is released, except when putting within 10 meters.
So, a legal jump putt requires you to release the disc prior to losing contact with your supporting point behind the lie. The advantage of a jump putt is not that you get to release ahead of your lie.
The advantage I guess, is the momentum of the jump helps to carry the disc so your arm can be used to direct the disc, instead of power it. I also think the rhythm and loft have something to do with it. If you use a jump putt, you are required to time your release so you don't violate rule 803.04.
As Harry Putter indicates, there are also other methods of imparting momentum, rhythm and loft to your putt. I would not say that the jump putt is the ultimate method, but one of many effective methods.