Read: Békéscsaba (LHBC) not to play the smart-ass, but to help in searching the www.
Second the positive remark about Koblenz EDRK, surprised though to learn they'd have immigration there. Their own website confirms: "Custums clearance has to be requested at least 2 hours prior to estimated time of departure/arrival." I reckon they too are mixing up "customs" with "immigration" - if not there might be some nasty surprise.