I sometimes use a combination of the both of them. in my 'style' an event to get a list? I dont like. Basically you would need 2 event to supprt that, one to signal "I want the list" and one that says "here is the list" I actually thought about this a lot because keepassFX has two threads running. There is the use case (we worked on that yesterday) where the server thread needs to ask something from the FX thread and needs to wait for the answer from the FX thread. this could be solved actually with coroutines (ask.await()) but there is (to my knowledge) no "send an event and wait for an answer"