Trying to understand and apply what you explained I have these values
AspectRatio = 16:9
AutoU1 = 0,6997167138810198
AutoV1 = 0,4048223350253807
AutoU2 = 1,11767578125
AutoV2 = 1,399746192893401
Inmediately after to apply these values I ran the game and crashed and closed.
Once I had the X and Y values I divided them by the top width and height and I get AutoU1 and AutoV1 (as I defined them), after these X and Y values I divided them by bottom width and the same height respectively, so I don't know if I made it good, what I was wrong.
Note: I think it's not pretty simple as you say, as example you'll see that it's not working for me, I see that you have a high knowledge of photoshop, computing code according to what I see and this must be piece of cake for you maybe, but I can't make it.