The Double Jump and further iterations of the jump armour modifier from tinkers construct for the traveller's gear does not activate at all. I have tried using just the double jump without any other gear and using it with the full travellers gear but it still does not activate.
Hmm, I'll take a look into this issue if I have time later on - assuming no one else finds a solution. If the double jump from TiCon is broken, I can most likely (slightly edit) my Bukkit double jump code to activate if a player is wearing the specific TiCon armor. I strongly believe this is a problem with TiCon but I could be wrong.
the Ender IO dark steel armor works with the double jump enchanted on it, but uses tons of energy though and you need lots of lvls.