I spent some time creating this mind map to sum up everything you'd want to know about the scam messages, as well as the common theories. I will try to keep it updated. If you have anything to add to this or critique, please let me know.
Might take a while to load, it's a very high res image. Here's a link alternative: https://files.catbox.moe/csls12.jpg
This should be obvious, but due to the recent developments I want to have this here as a warning:
Don't send the scammer any money, even as a joke.
What % of the instances these are coming from are instances that require email also would be a good thing to collect.
Most of the used instances are abandoned without active moderation and even with the email requirement, there isn't a built-in way for lemmy to filter out temp mails. The abused instances are unlikely to have automod running.