I would note that people shouldn't start furry conventions just to have the goal of holding a record, and they should be reflecting their accommodations toward their own educated estimates, not on previous record holdings.
If that is of concern about it being an unfair advantage bring in an area of a previous convention, then one could always separate it into "successor premier" and "geographical premier"
Where successor is a convention that starts in an area (20 square miles) where a convention used to be in the last 5 years and geographical would be an area that had no previous furry gathering in 20 square miles.
I would note that people shouldn't start furry conventions just to have the goal of holding a record, and they should be reflecting their accommodations toward their own educated estimates, not on previous record holdings.
If that is of concern about it being an unfair advantage bring in an area of a previous convention, then one could always separate it into "successor premier" and "geographical premier"
Where successor is a convention that starts in an area (20 square miles) where a convention used to be in the last 5 years and geographical would be an area that had no previous furry gathering in 20 square miles.
If one cared to differentiate the circumstances.