PB return value by use of events (idea/concept)

Some of you might have encountered the problem of PBs not being able to return a value to its caller. I know, this is kind of rare.

Theoretical problem:
You made library wich you're using in some of your scripts.
This library migght have grown to a point where it consumes to much space to be included.
You think: "oh well! why not put in into another pb an use it like an API!?" but then it hits you: PBs dont have any return value (besides using an lcd or customdata as buffer/cache)

I might...

PB return value by use of events (idea/concept)