Hey TomG,
Glad to see you here.
My idea is to use Gaussian as an environment for animations and stills. If we could use (not sure if possible) the geometry + textures from 3DGP, that would be great. So, basically, all we need is to take videos on overcast days (not hard in London) and then use them as our environment. This way, we will have the real world inside our software as the background and can add our project in the middle of it. Of course, all 3DGP elements need to receive Corona sun + sky light, and even simple Corona lights, receive and cast shadows, etc. Essentially, replace the context of the project.
I would be more than happy to help.