Are you looking to using these templates, or are you trying to fix a compatibility issue with a specific truck mod?
It provides high-resolution 2D wireframe layouts (templates) that show exactly where graphics will appear on a 3D truck or trailer model. TEMPLATE FOR TRUCK AND TRAILERS BY SCHUMI V1.0 ...
While "deep feature" isn't a standard technical term in the game, it most likely refers to the this mod provides for Schumi's reworked truck models—such as the DAF XF106, Iveco Hi-Way, or Renault Premium—which often have different geometry than the base game vehicles. Key Details of the Mod Are you looking to using these templates, or
Template For Truck And Trailers By Schumi V1.0 ... Link