Update: A few months later and still no password… The short story: after thorough investigation, there is no easy and/or low risk way to obtain the program.

A more detailed story:
All the “password recovery” solutions I found were resetting the memory instead and Siemens support couldn’t do anything about it due to potential “legal claims”.
I found one potential way to obtain the password (something with reading data directly from two pins of a chip), however, estimated too risky without the guarantee for success.
Ended up with completely reverse engineering the machine by studying its functionality, reading the wire diagrams & following the wires in the field and theoretical studies about the process.

It was a fun experience 🙂

Thanks for thinking along and till next time!

Thank you very much! I deleted the “rubbish ;P” and now it works perfectly.

Have a nice day 🙂