Okay, another thing that seems to be "bugged" with those map settings... (especially looking at Cell size being 3.75).
There is a problem with correct transition between ground textures. I am totally aware of materials limit per cell. Everytime I regenerate my layers, Im using "6 materials per cell (Arma 2)" setting and I also do a double check of my mask layer with the custom tool called MaskColorChecker to see for any tiles with exceeded limit.
But textures after regenerating are still wrong, they have sharp edges and sometimes they inherit something from wrong materials. Example on the first attached photo.

I even tried to basically remove almost everything and I left out only 3 different materials (grass, tarmac and dirt) and the result is almost the same. Leaves on edges are not present anymore but they are still too sharp in comparison to other borders.

I'm a little bit surprised that there are such problems, because according to this website https://pmc.editing.wiki/doku.php?id=arma3%3Aterrain%3Agrid-cell-size my map settings are exactly the same as for Arma 3 map called Tanoa. I dont own Arma 3 so I cant check this, but Im pretty sure that this problem does not exist here...

Update for the previous post.
I noticed that on official Livonia map there are same bugs, for example transition between grass and dirt has leaves from forest, when in reality forest is further and does not touch this place.