Here's the version 1.2 of the YafaRay rendering plug-in which fixes the projection of the fisheye lens to make it similar to SunFlow's one and improves the launch delay of the renderer, mostly for scenes with large texture images. As this version creates much less temporary files, users with a slow hard disk should also see a faster launch.

It's based on the version 3.4.4 of YafaRay that David Bluecame kindly released to add more projection parameters fo fisheye lens.
I forked this version to avoid storing texture images in temporary files and to speed up the rendering of multiple frames in videos, an improvement that Enkonyito will hopefully integrate in his plug-in.