A lot of standard breaks have the CB in the air most of the way from the cue tip to the head ball. {you can see this in the cloth wear after the tournament is completed.}
Should this also be outlawed ?
Seems to me if CB leaves the bed of the table even a 1/100 of an inch it should be considered a jump shot. {This is basically the same analysis as the double hit.}
If not then you are only discussing how high off the table CB is allowed to go before becoming a foul.
If the jump shot in general is made illegal, it's pretty easy to know when one is played. It's like the scoop jump which is illegal and an accidental miscue. Anyone that is not trying to be an ass on purpose and knows how to play would be able to know one from the other.
I do feel that the jump shot, without a jump cue, is a sufficiently skilled shot to execute that I don't see any issues with having it in the game. And I would much rather see that happen than this push towards 4" pockets and messing with the break rules at every other tournament. I mean look what happened with that horror of a 3 point rule, there were perfectly good decent speed breaks where a ball or even two were made, and the player had to go sit because some other ball hit the point of the side and did not go past the line.