Having often found myself frustrated by Steam Workshop's content restrictions, I'm wondering about the possibility of DTG's setting up a similar site with few or no content restrictions. For example, I prefer making switching/shunting scenarios and frequently find myself wanting to incorporate rolling stock from other providers, such as Michael Stephan's excellent models. I'm familiar with several TS-related forums that accept scenario postings, but would really like to be able to share my work more directly with TS enthusiasts. Any chances of this happening?
Hope this helps, but the main website where people can upload scenarios that use 3rd party assets is UKTS (UK Train Sim). UKTS would seem to be the best solution to your dilemma.