My suggestion is to add tab sorting :)

This will not be implemented in PowerRanks.
There are other third-party plugins that have this functionality that work great with PowerRanks (with the use of vault and PlaceholderAPI).
PowerRanks 'mostly' only uses features present in the BukkitAPI and tablist sorting isn't one of them, meaning that packets have to be used and that will break compatibility with many versions.