Thank you!! ^^
Yep, the limitation of two buttons make the combo necessary to avoid activating wrongly the teleport by pressing the buttons in platform movements. The trick in the teleport combo is press J+J +K (or K+K+J) , but mantaining "K" (or "J") pressed a little bit more time. The level 2a and 2b has "a lot" of space and time to get used to this controls and for training.
Other trick, not told in the game. In air, it´s possible to make more teleport movements only with J+K if you are fast enough. And there´s a "hack" involving that: when the time is slowed down, you can travel almost all the levels enterely with teleportation, hehehe. I forgot to deactivate the device in slow down time messages. I used that to "fast travel" in order to check last changes at the end of the level XDDD.