If you file a vfr flight plan before departing then all units along the way get details through the AFTN system and this again reduces the details you have to pass.
A common misconception - VFR plans only go to the destination and the alternate. The computer that routes the plans doesn't know where to address them with regards to en-rte agencies (unless it was addressed to each one individually).
Notwithstanding this the actual practicalities of having the plan are non-existent. I for one am not going to make up a pile of strips for flights which may or may not call (no where to keep them ready anyway at summer traffic levels) but if this was to be done then there'd be no way I'd have the time to actually find the strip when the aircraft called if there were so many. Direct handovers or info when you call are the only practical solution at the moment.
CM