I think a 'document adder' could save allot of time and increase AudioMulch's creative flow, by allowing users to add entire projects to their existing project. This way: if you have a combinations of contraptions that you want to use in the future compositions, you could save them as a projects to be added in real time during future composition or performance.
A document adder function could be thought of as an advanced function, as it would require the user to understand how to manage their cpu load and anticipate possible glitches in the audio caused by the loading of audio files. However: if used properly it could potentially allow Mulchers improvise more efficiently by adding macro elements that have been created in advance.
Importing controller setting with the document might be a helpful optional, as would an option to automatically connect an added document to the output contraption.
If Mulch kept track of what had been added from where: a parallel 'Delete Added Document' function could remove specific added documents. This would allow users to begin their set with nothing but an add/delete document window open and proceed to take their audience through a vast array of pre-composed elements and complex sound shaping components.
A work around might be to allow copying and pasting between simultaneously open AudioMulch documents. This way: one document could be used as a pallet, while the other could function as the performance environment.