I'm not sure what else to tell you. The frame buffer is patched correctly, I'm not sure what's going on with your computer. I guess as a last resort you could technically use the yosemite frame buffer on El Capitan and see if that does anything.
I know... I believe you 100%. As for the other FB from Yosemite, I tried that one also, but it ends up with a scrambled screen, this is so weird. I need to use Natit until DSDT is patched though, right? Last time it took me a while to get it all working but eventually it did. Might I need to force the resolution or inject Intel in the clover settings?