I've noticed on latest DLE-XP version, that it loads just part of the mod data when loading a mission with mod.
When loading ASE models, it just loads the global models of the mod (mods\missioname\models), but not per-level models (mods\missioname\models\levelxx).
Also, on 1.11.16 it loaded mod textures almost right (although unfortunately it only loaded per-level textures), but now on 1.11.19 it doesn't loads any mod textures at all, not global, not per-level.
As a side note, a good way to test the mod data loading functions for both global and per-level textures would be Pumo Mines Level 3.
As textures, most level wall textures of level 3 are on its respective per-level folder, but the door, water and lava textures are global,
while regarding ASE models, level 3 features global models for the crates, barrels and stuff, and per-level models for the trees and the tranmission tower for the terrain. Pretty good for testing. :)