Replacing buildings on a builder - possible?

Just curious if it is possible to change the buildings a unit can build with JASS, as it would probably be more efficient than replacing the building with a different one every time its built.

I don't belive so. Not positive. I have never seen it done before. Perhaps you could use the ability Chaos. Not sure of the effect.

What happends if you add all structures to the builder, then use this to hide the ones which are not available?