ISpread<ISpread<ISpread<double>>> output pins possible?

ISpread<ISpread<ISpread<double>>> FOutput

seems to output NIL.

Are we limited to ISpread<ISpread> (apparently this automatically generates a bin-size ouput pin too)?

as far as i know that only works as pin group, not as single pin

edit: nope, not even as pingroup. only remembered elias had a special case for that