The only way I could see that happening is to double the screen size and processor power of the PN-20. I realize that the SD capability gives lots of storage space, but I'm sure I'm not the only cacher out there that loads TONS of waypoints based on everywhere I MIGHT be going on a trip.
GSAK handles waypoint management by allowing me to download GPXs all at once in preparation for a trip and then slice and dice them at will. From there, I export various filtered views into Topo 7 so that I can toggle between All caches, Ones I haven't found, Easy ones, Non-Micros, ....
Unfortunately, that's where it breaks down right now. I'd like those segregations to remain when sending them into the PN-20, but at 200-500 per filter (sometimes more, remember GSAK is combining the 500-limited GPXs into one GPX), the 1,000 waypoint limit in the PN-20 looms quite large.
So, for now, I simply delete all caches (by symbol) in the PN-20 and resend the view that I'd like to have portable for a particular outing. Non-Micro easy ones for travelling, Ones I haven't found when alone, Everything when I'm out with others.
Works well, but I can't see the PN-20's current hardware meeting the needs of THIS particular cacher.
Lynn (D) - aka CodeWrangler - PN-20 owner & AT&T Tilt user