Yes! We've been forced to convert all participants to constituents (driving up our record band for billing) just to be able to send out emails related to an event someone is scheduled to attend.

I would absolutely echo the need for this. Particularly as we're trying to integrate with OnEx - which creates hosts and guest - if we're want to send details about the event to all of them the only way we can do this is by making all the guests participants. I suppose the problem is what it would add the action to as there is no participant action functionality. Even better though would be able do this in Online Express.