Hi, Colin.
Thanks for your interest inĀ Community Events.
We don’t have any duplicate post detection or prevention, and I haven’t personally heard of this use case for it before.
You could request this as a new feature (or maybe search to see if the idea was already posted by someone else) at our plugins’ UserVoice page.
This allows others who are interested in that feature to easily voice their support. We frequently review suggestions there to find out which ones are popular, then we implement as many of them as we can.
If you post it / find it, feel free to link to it from here in case anyone comes across this forum thread in the future.
I would recommend searching online for existing solutions. One of these look good (third-party, not guaranteed or supported by us):
Please let me know if you have any follow-up questions on this topic.