Currently most values of the server.properties are accessible except 'enforce-whitelist' which is rather new to the file. It would make sense to implement a method like 'isWhitelistEnforced' to access this value easily and let plugins act accordingly.

Other options currently are:

• Reading server.properties separately
• Using NMS

Both of these options are in my opinion way to overpowered for such a simple boolean and I hope this becomes an API thing.