How exactly should it work with properties @type, @baseType, @schemaLocation in case they are presented in _MVO schemas? For example in Product_MVO (TMF637), where Entity_MVO is inherited, which in its turn inherits Extensible schema. So at the end you have all these 3 properties available for update that doesn't look plausible.
One more point: there is no Extensible_MVO schema in specification and I find this reasonable. I can suppose that there are some problems with schema generation with Entity without properties, but just a guess.
------------------------------
Anna Berdnikova
Deutsche Telekom AG
------------------------------