Referencing a class in [Event] metadata (ie. [Event(type="something"]) has the same affect as referencing it through code: the class is linked and included in the output. Is there a compiler flag that will allow me to enable class linking for my own metadata fields (ones that were included via -keep-as3-metadata)?
If the answer is yes (if not, you can skip this part), does that functionality "stick" to libraries like -keep-as3-metadata does? (ie. if you -keep-as3-metadata in libraryA and reference it from applicationB, applicationB will also keep that metadata)
Unfortunately, the answer is no. You would need to write a custom asc extension and adding this type of extension to the compiler is currently exposed. Please file an enhancement request.
No worries, thanks for letting me know.