Variety.

This is related to the map size. In the classic version, with 5 heroes, the programmers weren't very good at programming virtual arrays, IMHO.

Yes, there are issues with maps of 320x320, ranging from significant slowdowns (although it's possible that my computer is just too old) to excessively large save file sizes, which, as a result, cannot be loaded. While the map is still in its early stages, I would advise you to seriously consider switching to smaller scales (you can try moving objects by copying and pasting).