Non-specialized server parameters are currently implemented via the ServerParameterWithIDLStorage class. This class uses the cpp_vartype IDL field to determine what type the backing storage should be. However, it is only capable of coercing the BSONElement into a primitive type (i.e., booleans, numeric types, strings). 

After SERVER-62255 introduced a base class for cluster parameters to inline, a new ClusterServerParameterWithIDLStorage class should be implemented that ensures that IDL-defined cluster server parameters can be attached to IDL-defined in-memory storage via the ClusterServerParameter type.