Hmm... I knew about the full-fare cancellation trick, didn't think about the ultra-low fare one... So I should not get into any trouble, if I book E-fare (48E incl. taxes) from HAM, check-in, and then cancel the ticket? E.g. should I cancel it only after entering air-side (otherwise it could be treated as fraud, right?) AND can I just go to gate agent and tell him/her that I am not flying?

(Not a big fan of doing things "the other way", but I guess it's a "no-harm" situation, and I don't think MAAS will work in my case...)

Thanks a lot for your help!