Mods that introduce a new male body mesh with different UV maps will have some odd stretching. All males in the game, regardless of race, share the same base diffuse skin texture, so the texture isn't compatible with other male texture mods. However, each race DOES have its own normal ...
Revert to Oldrim format using NiTriShape converter, by opparco (https://www.nexusmods.com/skyrimspecialedition/mods/19911) Duplicate geometry to have faithful havok model; duplicate the file (or make a new one in Blender with fewer polygons) Use ChunkMerge from NifToolsSuite to merge (s...