Remembering that "perfect" is the enemy of "good", I suggest allowing 2 or 3 asterisks on a .idl file line. Two will cover almost everything. Three will cover 100%. This assumes that a generic N-level implementation would be harder to implement. It might not be.
How far are we with this?
yeah, support for N-level isn't any harder.
Moving PIDL bugs into Samba as we do not release PIDL separately.