And we’re sorted! Out of shear desperation I deleted D3D11.dsp and let it regenerate, got into 3D flawlessly.
Lessons for today - don’t mess about with Streaming Assistant, go straight for Virtual Desktop. Don’t forget the old favourites too!
Performance is beautiful, solid 60fps (might need to disable Vsync) and butter smooth, can even read the small writing.
Thanks to you all again for trying to help, hopefully this thread will help others in weeks and months to come.