We were asked about maximum map sizes, and we won't have exact numbers until a beta build, but we came up with some size examples that will give you an idea of where we are at with our alpha build.
For the question of map sizes within the program, we created a 9000 x 9000 pixel map (not a particularly detailed map, it's just an example). At 300 ppi, that would be a 30” by 30” map.
We added that map to the maps in the campaign (under What We Are Working On)
The other part of the question, is the maximum size Other World Mapper can export scaled maps (landmasses and other objects are vector based, so there wouldn't be a loss of resolution in those from the scaling). And the answer is very very large. We've tried exporting maps successfully at 17000 x 17000 pixels (56'' x 56'' @ 300ppi).
We are going to continue exploring the limits for the size of exported maps and in-program maps and we'll keep you updated! Until then, we hope these numbers help!