I have had 7 jump cues.
What i have found is this:
The jump cues that are the lightest, kangaroo ( illiegal I think) , and the one with two shafts or tips on either end, jump the best within an inch between balls. Because of the weight.
Next are 3 piece jump cues such as predator air or air 2, lucasi air hog 1%2, ob lift etc. With phenolic tips i can even execute illegal jumps ( where the the cuball rides up the shaft) see dr. Daves website.
And 2 custom obscure cue makers dedicated one piece jump cues.
With the 2 piece, phenolic tips allow you to get the ball up quickly because they are hard enough to " pinch" the ball between the cloth/ slate quickly. They are also light which helps with speed as long as your grip stays loose. They also allow for jumps that are more then 2 feet+apart with the third piece
The one piece cues tend to be heavier then the three piece cues broke down to two, which makes the acceleration suffer ( this is probably arguable).
In conclusion I have found that a hard/very hard one punch leather tip allows for the most control amd consistent results on a 3 piece jump cue of your choosing.
Technique and allowing the grip hand to stay loose, so the cue goes on a straight plane is more important then the cue.
Good luck, jump shots are a risk and tough no matter what.
Efren usually kicks and I believe he knows whats best.
<<<<<< plays mediocre at best so take with a grain or two of salt. Though I have spent more then 100 hrs. Of dedicated jump practice.