I'm going to try to fix the issue that shows a different mapping of a sky texture in the 3D view and in SunFlow...
Maybe, it is just me, but it would be a great help if 3D view and rendering were the same. And even better if I could understand the projection and manage to make a reasonably accurate template... 
Sorry for messing with your thread Cec, but I could not help thinking about the vertical scale after more testing with your brilliant template. And although I am mathematically challenged, maybe it is as simple as calculating the sine of the angle to place the horizontal lines (???). I put it into an .svg template (which again can link to a panorama file for scaling, link is Inkscape compatible).
pan360.svg
The pan360.svg links to file pan360.jpg (same directory), e.g. a Tromsø panorama to study stoccafisso and hjell-building:
pan360.jpg (3600×900)
Test rendering using sine of angle to place each horizontal line above horizon. At least it looks better.
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