I remember seeing a vid on YouTube. The fixture was made from white vinyl gutter troughs and PVC pipes that made the fixture fold on top of itself. It was quite neat. Not sure how I found it. I'll see if I can find it again..
I had a very similar idea, but with metal. I have no need at the moment since I only have one light. If I add another (which I have been considering) I would definitely do my own version of this. I figure but if you get stock "bar" metal and drilled the ends, used some washers and locking nuts it would work the same and be much more elegant looking. An angle bracket could be used to limit the movement of the lights rearward to stop them and "hang" it over the other fixture when you work. I would MS paint what I mean but I am left-handed and it would look terrible. Maybe I will draw something up and scan it.