My previous experience with connecting to Jetstar from LH using air side transit:
- first attempt: we can't do that until Jetstar check-in is open, that would be X hours before flight departure
- second attempt (within x hours of departure): we can't do that because Jetstar doesn't have an interline agreement with LH
And I agree with tentseller. Air Asia is so much better than Jetstar, in the air and on the ground.