Sorry for the delay, I haven't been playing with the camera lately. But I really appreciate your effort.
I tried the patch you made, and it works really well! There is just a small user-interface glitch; in LIVE mode, the overlay appears correctly on the screen. After shooting, during the preview the overlay is shown all messed up again. So I first thought it didn't work. But it actually saves a proper overlay to memory. What happens? The overlay is saved twice? It's not a functional problem, it just behaves different than expected.
Anyway, great work and thanks for the patch!