Unfortunately, I did not understand how the NxN mode works. For example, I set the width to 10, the height to 10. In the NxN section I put "1x100 100x1". In the game, there is no NxN (1x100 and 100x1) merging, the chests are merged into several 1x10 and 10x1.
In order to enable area merging you have to have large enough width/height/area limits and then whitelist should contain either "NxN" or "10x10" if you want a 10x10 chest. If you don't need list specific whitelisted chests sizes, use the "NxN" whitelist.
As I understand it, the whitelist (NxN) restricts the creation of all other chests? And also the chests specified in the whitelist can not exceed the specified maximum values of width and height in size?