I mainly use SQL Object types in the PLSQL context, as it allows to create interfaces with multiple implementations. As field types in SQL types are bound to pure SQL definitions, it is not possible to define a field as a reference (TABLE.COLUMN%TYPE) or as a associative array.
It would improve the quality of our plsql code base if this kind of definitions in SQL types are possible, or if a similar PLSQL only type would be possible.