This script only handles cells on the first visit, resetting if the cell file was not present on server startup.
That means, that only cell reset scripts that actually remove cell files will cause creatures to be re-duplicated.
One such script is my own CellReset.

Requires DataManager!

If you choose to use it, require DoubleTrouble after CellReset in customScripts.lua for them to interact properly.

You can find the configuration file in server/data/custom/__config_DoubleTrouble.json.

• minimumCopies minimum amount of copies of the same creature that can spawn. The default value is 3.
• maximumCopies maximum amount of copies of the same creature that can spawn. The default value is 7.
• creatures a list of all creatures' refIds that should be duplicated. This is largely arbitrary, feel free to change it.