Yes but correct me if I'm wrong, if you render the layers at 3000*1000 and stretch that image to the tube it will have the correct proportions and ratio but would there not be a huge loss of quality ?
For example if I take an image that is 1000 px large, stretch export it to 300 px large (with same original height) and reload it and stretch it at 1000 again, quality drops very much.
So your question still stands, what is rendered in what order, but somehow even if the image shortly is stretched and applied to a 111 tube it perhaps still has access to the original image so that you loose some extra hardware work but at least your image would be at better quality ?
;) No probably not. Try using Copy List Items with Interleave Lists and if that works just do the same 4x (connected for one corner). Splitting the 4 corners would allow you to set different colors for each corner f.e. !?