I have often wondered about the EU automated gates. For instance from LHR if I take BA into Munich T1 I still have to get the physical stamp in my Canadian passport but if I then leave from MUC T2 I can use the automated gates to exit. I've never done this because I don't like the idea there is a stamp in my passport for entering but none leaving. Just think it would cause an unnecessary hassle. Hopefully if ETIAS ever gets up and running this stamping will be a thing of the past