DELTAGEN usually stores paths to textures into the texturepath file which gets saved together with model data. We observed in certain scenario that an unusual high amount and mixture of local and network paths in that texturepath file can lead to increased model loading times. Especially when those network paths have to be reached over the internet or remote.
Open the texture path file with a text editor of your choice, and check if there are unneeded file paths. Furthermore check if textures can be stored locally.
The loading times in the examined scenario went from 1,5 hours down to a few minutes.