Yes AoB will affect the outcome. The closer you are to 0/180 AoB the less accurate. But for most purposes the 1.94 formula works pretty well. I tend not to shoot outside the 70/110 AoB "cone" if I can at all avoid it so it works well enough
And the cooleo thing about this formula is that you don't need to know the range to the target. It took me a long time to believe that (and a lot of graph paper) but it's true.
I actually use both the 3:15 and the 1.94 formula depending on the circumstances