“Manual Check” be done only through code by having a reference of the state, which for example you can get with the API of the FSM class and was initially added only for being used through code. HOWEVER, I would advise against it since it is something that is definitely going to be removed in future update since it is rather a leftover feature that sometimes confuse people.
With that said, “Check Event” condition task, even every frame, in itself has pretty much zero performance impact since its update code is simply this:
Regarding your 2nd post about the transition not happening, I just did a test and it’s working correctly. Can you please confirm that the Check Event and Send Event are using the same name (its case sensitive) and that the target GraphOwner of both are the same GraphOwner?