Currently there is no guarantee that a Condition group (= if/then/else structure) or a Decision group (= case structure) will not block, since they have no unconditional else branches to do catch-all processing. These need to be added.
They are not needed on EVENT_GROUP (since the timeout will take care of things) or ADHOC_GROUP, since this is a user choice structure.
Original modelling attempt reversed. We will discuss the best approach further, post 2.x release in which the TP model is separated from the Decision Support and Proxy models.