Thanks for your input. I am doing something similar. I am allowing my users to schedule up to 4 different events at once. So I am writing those events to a custom collection in addition to using the createRSVP API to register them on the client side. Unfortunately, I had a situation where 2 of the 4 events made it to the collection and 2 failed. Luckily I was monitoring the events and I caught it. I started out first using the events on the backend but ran into a similar case. Again, I am presenting 4 events to the end user and using the createRSVP API. Sometimes this API fails to successfully register which in those cases the onRsvpCreated doesn’t fire.
Last I have resorted to catching the exceptions while persisting to my collection and then creating a Task to I can at least capture the failed attempts.