Apparently 6 posts per IP per hour goes over the limit. However, just changing my Tor circuit enabled me to post my last crosspost.
Should quotas be per-user not per-IP? Some people may share the same IP in a legit manner after all. Also, should crosspost count as posts?
6 post per hour is too restrictive in the first place. Maybe a post each 15 to 30 seconds is better.