It is possible to create another application in Doc Mgr to store these types of drawings. We have created a seperate application with a unique regapp so that drawings/plans etc. are stored under a seperate node in document manager and save to their own project path. Here is what our Doc Mgr looks like:
So, we create a GA drawing un der the drawing application initially so it is assigned that regapp, then load piping on it after the fact. This keeps it seperate from the models.