Config opinions to restrict users on the max/min size of regions they can create.
Something like this in the config-

limits:
plots:
Max:
x: 100
y: 100
z: 100

Or something similar. Also permissions to override the limits and/or permissions for each restriction so you could define restrictions for the default group different than a vip or admin group.

Accepted

Implemented in commit 2877a52

New example config is here: https://github.com/jmhertlein/MCTowns/blob/2877a520ad15ac94e8584ea8eb988d03f0acc502/src/main/resources/config.yml

Documentation of the feature is here (in the second table): https://github.com/jmhertlein/MCTowns/wiki/Configuration