As much as I like the idea, you may end up excluding some of your members who would normally participate. I, for example, would not be able to 'finish' some one else's map, UNLESS it was someone that uses cc3+, AND if that some one had included their fcw in the thread, AND if I had all of the annuals they were working with. I could also 'finish' a map made in Fractal Terrains, but again, only if I had the ftw.

Hand drawn maps, or maps made in any other digital format, I wouldn't be able to 'finish'. I would have to recreate them. Which would be importing a traceable image into my program, then hand tracing each element of the map, using what symbol sets I have at my disposal. That's not the same thing as finishing a map.

Now if you included an option to recreate someone else's unfinished map, and THEN complete it... I, and others like me that have a non - compatible program would be able to take part.