What to do with Protégé's and OMV's OWL-specific metrics?

[clange]

Protégé and OMV define several metrics that only apply to OWL, e.g.

• omv:numClasses, omv:numProperties: in LoLa's more general terminology, this refers to the number of symbols per kind, but as ontology languages may define an arbitrary set of kinds, we can no longer easily represent this in OWL unless we hard-code one such property for each kind of each supported ontology language. We need not restrict ourselves to OWL, of course ;-)
• protege-metrics:maximumDepth, protege-metrics:maximumNumberOfSiblings: this refers to a class hierarchy, which clearly exists in OWL, but which may not always exist in other languages.