Darn.  I actually had a DEV template modification that demonstrates some of this, but I removed it from the published package because I thought it was too niche.  See a screenshot below.  I also need to use a subVI to name the event registration.   You can also see a “Private Messenger†in the JKI Actor Template. 
  
Note, BTW, that I don’t use EventMessengers in the way you are: a different Messenger for each message.   Instead I have multiple messages coming in through one event case, with a case structure on the message label.   The only reason I sometimes have a second EventMessenger is to separate “Public†(or “Externalâ€) messages from calling code, from “Private†(or “Internalâ€) messages coming from my subActors.  So I can prevent calling code from being able to send me private messages, and I can limit what subActors can do (like not tell me to shutdown, for example).