How would you submit realistic 3D renders (not the interiors that need to be submitted in a specific way but, for instance, say a cup of coffee on a table)?
My logic being, if submitted as photo it would get a wider exposure since a particular buyer might be looking for photos and assume illustrations might be more of a vector designs and similar.
Or would you call that cheating, in a way?
How do you submit realistic 3D renders?

I haven't submitted any 3D renders for months, but the last I recall SS and DT and I think also Adobe required that you include certain specific words and phrases like "3d render" in the keywords and sometimes in both keywords and title. SS was very picky about it.

I think that's a must for 3D rendered interiors, for the purpose of not needing property release from owner/designer if it was a photo, not much to do with a way the image was created. I understand that.
If it's good enough, there's no way they can tell photo and 3D render apart.

Yes that would be an illustration if that's a full 3D render.

If your artwork is a mix of photo and 3D render, then it's more of a gray area.