In 2.3 the image must fit in your computers memory to be converted to MapLib.
Once you have converted the image to a MapLib, you can handle files that in compressed form is maximum 4GB in size. Very large MapLibs will also take some time to open the first time they are accessed, when GpsTools makes an index of its contents. This is not problem on desktop but can take some time on Pocket PC.
Here are some things to consider:
1. Rather than assembling hundreds of maps into one single MapLib, split them into several MapLibs and load them at run-time using Map.Merge() This is necessary on Pocket PC, and when the MapLib file size exceeds 4GB.
2. Rather than assembling many raster images to one gigantic map, divide them to several maps that has overlapping edges, then use Map.ActiveMapData() at runtime to switch between the maps. The user will not notice the switch. This is importaint when you are dealing with very large single images, that doesn't fit into memory at development time. (At run time the algorithm for loading is much more clever).
We are currently working on an update for Studio that can import images of any size.