About model and data exchange with 3rd party solutions: Revit, Solibri, dRofus, Bluebeam, structural analysis solutions, and IFC, BCF and DXF/DWG-based exchange, etc.
If you open a drawing for editing (i.e. then save as a PLN) before including in your model (by hotlink or whatever) it would be great to be able to add a prefix upon opening....could not do it up to 12 - yet to try out 13...
rtw is correct that if you xref you can get a prefix to the Layer name. You could always add a standard pre-fix to the front of your layering system to try to clump your Layers together ( ie aa_ )