If you are asking for him to sell the map directly, unfortunately not. As I mentioned in the description, it seems to be impossible to create an explorer map trade with commands, hence why I needed to use a chest with a custom loot table instead.

And if you are asking for it to "locate" a new city you haven't been to, that is possible utilizing a feature called skip loaded chunks, but I decided not to have it do that since cities are already very rare. Just travel to a new area before using the chest if you want to maybe find a new city.

you could go into the function found in data minecraft funtions and then change the Count nbt to 64

The way exploration maps work, it locates the nearest one I believe. I also have skip loaded chunks as false, meaning it will locate the nearest one even if it is already loaded. If you have already searched that city, try to find a wandering trader far away and hope he locates another.

Yea, apparently they are more likely to generate "inland" I believe, the same conditions where mountains are most common.