That is correct
I had thought about their schedules which is why I even put in there a bi-annual options (every two years-ish). I didn't think everyone would always want to be spending time on these things but it would be nice to know its coming so those wanting to participate could plan ahead a bit.
The other side of that coin also thinking of the leaders, if it is a scheduled thing you may not have people asking repeatedly for them, and it is something for the group to look forward to.
As for utilizing the leaders time, I don't know what they would think about this, but it could be an excellent opportunity for others to learn new techniques and skills (such as making a zoomable map, or just taking the time to merge the maps) This would take some of the responsibility off the few who currently are maintaining that.
Or in some cases, as mapping out buildings within the city, the actual final linking could be done when whomever does that has time, and not much (or any) pre-planning with an area and topography map needs done.
I'm still new here so, I am not sure how tight the reigns are from the leaders here on these sort of things, but some of these ideas only need someone willing to organize and encourage them. I'm not saying we should plan on excluding anyone, but if their schedules are too heavy, there are things we could do to help out and still make a successful project.