Thank you both for your answers. my mental scenario is that I actually like "classic" circuits (they work comprehensibly and have for many years), but at the same time I would like to at least enable "smart home" functionality. The idea is: I install a classic circuit (for example in the hallway: a three-way switch circuit with three switches for the hallway lighting) and prepare so that a fourth electronically controlled three-way switch could hide in a flush-mounted box. This makes me very flexible and would combine both worlds cost-effectively.
The suggestion from seems to fit. I had to search quite a bit to find something reasonably understandable, but for example the eltako ESR61M-UC seems to be able to do that. In my initially classic installation, I would have to provide space in a flush-mounted box and lay a control wire for the impulse switch there. The control wire then goes from the eltako to where there is more "intelligence," probably a microcontroller on Ethernet.
1. Was that understandable? 2. Could that make sense (I know many alternatives are discussed here)? Or would it be obviously more reasonable (for professionals) to plan the entire installation from the start with push-buttons and impulse switches?
One more note/question: I love the Berker 1930 switches. Is there even anything like that as a push-button/impulse switch?