SimIo - add-on processes, UserExtentions and Returnvalue

Question

I have a question about dealing with SimIo from the scope: add-on processes respectively UserExtentions.

In particular, the flow of information is unclear to me. The UserExtentions allow to pause the simulation process until the called interface is done with the calculation. Like in the example of the great Python api: (https://github.com/SimioLLC/RunExecutableStep)

But how can the return value of the UserExtention be accessed?

In the articles I found, only the global "States Variables" was only updated (like counters or similar).

Alternatively, I guess you would have to cache the result in Python in a .txt file and read it out with SimIo?

I appreciate any hints, regardless of whether they lead to success or not.

Best regards David