Mandatory and non-mandatory on changing 2nd pillar pension fund

I was motivated by the comments in that thread. But I didn’t want to threadjack, so I made a new one.

The two companies (of which maybe one is your own, with a pension fund chosen by you) are there exactly to prevent doing anything even potentially illegal. You mention it often.

In the mentioned thread there was the Descartes article from @markus654 :

But it names no source for their opinion. On the contrary, I think they don’t actually say anything about not having such obligation. They (Descartes) are cleverly using language to say something they didn’t. Later on they say:

Eine Variante ist die Aufteilung in den obligatorischen und den überobligatorischen Teil. Dies ist sinnvoll, wenn das Überobligatorium nicht in die neue Pensionskasse eingebracht wird oder eingebracht werden muss. […]

So they only say: If you split, you don’t have to send the non-mandatory part. Different from not splitting, which can’t give you a choice when you need to send the mandatory part. Sending the split-off non-mandatory part then depends on if you must or will. By “will” they, of course, mean: If the pension fund gives you the choice to and if you then chose not to.