As the title says, on the latest version the log occasionally is spammed with an message regarding Ravens spawning with duplicate UUID's.
When this happens, a barely noticeable frame drop happens.
Some times it happens once or twice, while some times it spams up to 4-7 times in a matter of seconds.

Same. Don't know how to reproduce, but I did encounter this situation.

do you have any error log? It will greatly help finding the issue.