Here is a new build.
Monkey4 is playable now in OpenGL+shaders with Fullscreen & Aspect Ratio. I hope I have only fixed things and not broken anything.
The issue was:
1. Using GL rendering with Fullscreen and aspect ratio correction force the use of Framebuffer
2. The intro screens use some cross-fade between screens using a screen capture
3. That screen grabbing is done with glReadPixels, not much choices, but that can be slow in GLES2 (and it seems especialy here with framebuffers)
4. The glReadPixels are done line by line, to put the texture in the right side (GL textures are upside-down).
5. And here was the problem, each glReadPixels was taking a long time (like half a second), and it was doing hundreds of them (480 in fact)... I batched the glReadPixels (and do the reverts with memcpy with a temporary buffer), and it's much faster.
*EDIT*: removed attached pnd, use next one, it's better.