would need
- list of all quests
- list of all zones relevant to each quest - unless you want a 6500+ entry dropdown (would have to be a listbox anyway, dropdown will be too long regardless)
- some way to toggle individual POI on and off - I remember I found such a way when map2 was first introduced and while I don't recall the specifics now I remember it was quite convoluted and would increase the size of each POI file by a magnitude and potentially introduce lag on maps with many POI (I think each POI needed individual UIscript).
So in theory it may be possible in some way but I doubt the advantages would outweigh the disadvantages. also keep in mind it will not be possible to tie that system in with SOE's existing system so it will just be confusing to people since they cannot know which system to use.