The AES can do whatever you would like it to do, with the only limitation being memory.  There is a document that gives a good idea of what the limitation of Adagio series processors are on Crestron's website.
Without seeing the complete spec and all things considered, you should be able to add the extension to the system.  First, if this system is currently running well check the memory being used on the processor before upgrading.
Was this programmed in Simpl or in SystemBuilder?