Self-explanatory: let us get an output of String Data out of an nPass loop.
Justification
This has already been discussed extensively on Discord, I just wanted to make a sort of reminder. 
My use case was the creation of L-Systems where two nPass loops need to be serialized: one that creates self-similarly repeating string and another one that parses it into an image. For that the string resulting from the first nPass needs to be available for the second one.
Thanks you for considering this!