Limited property types in Extended Classifications?

I'm trying to create a system using both types of classification to work out which might be best in which circumstances and have discovered that there seems to be quite a number of property types that can be used with standard classifications, but not extended classifications, e.g.:

  • Foreign properties
  • Sequence
  • Federated
  • Image
  • ...

Am I missing something here? If not, are any of these likely to be coming to extended classifications?

Thank you!