Just keep in mind that the coastline in many places (like the Netherlands or west Jutland) has changed greatly since the medieval time as well as many huge artificial lakes were created during the 20th century (like you could see some on the Dnieper and Volga).
I will be happy to update them to their medieval equivalent if you provide a map for reference to me. Otherwise, I will deal with that when I get around to looking up the material.
My map editing was mostly focused on satellite images from NASA as well as various NASA elevation maps (Due to the ease of conversion to game files as well as their accuracy). So, obviously, some of the modern dams, reservoirs and hydroelectric plants will alter the landscape.
So will this be a map texture mod like LTM or an equivalent to SWMH?
I'm not editing any of the individual map texture files (i.e. what the individual grasslands, mountains, steppe textures correspond to the Terrain.bmp file. So, if you use LTM, it will use the LTM files. Conversely, if you do not use LTM, it will not use the LTM files.
My map just looks different, in terms of terrain textures, because the coloring and lighting is different from what HIP currently uses (i.e. the Terrain.bmp file and colormap.dds file) which is a mixture of transference from satellite images as well as custom color editing by myself.