could it be a query endpoint like
https://domain.com/new-topic?title=My%20cool%20event%20topic&body=%5Bevent%20start%3D%222026-05-14%2012%3A00%22%20end%3D%222026-05-14%2012%3A30%22%20status%3D%22public%22%20timezone%3D%22Europe%2FLondon%22%20reminders%3D%22bumpTopic.3.days%22%5D%0APurpose%3A%20weekly%0A%5B%2Fevent%5D
I understand you can’t pre-fill replies in this way, so wouldn’t work for a purpose of Are there any plans to allow multiple events per thread or per post?.
I think the main thing i was getting at is keep all topic events in the OP, but have primary and secondaries, as per a poll that could also be in the OP.