I have just published an update that should fix this for first-time installs. Please check.
I'm also experimenting with a preview for the tone mapping. Still desperate for someone who knows this stuff to offer some assistance!
FYI I've got something like this going for each pixel:
r = (r*(A*r+C*B)+D*E)/(r*(A*r+B)+D*F)) - E/F )/ *W*(A*W+C*B)+D*E)/(W*(A*W+B)+D*F)) - E/F)
(repeat for g and b)
but this seems to always give me a number somewhere around 1, rather than a sensible RGB value between 0 and 255, so I am just multiplying it by the original pixel's r (and g and b for the corresponding lines), but that doesn't seem right. I also haven't normalised for gamma ^0.45 or anything else - not sure if I need to!
If anyone could shed some light on this would be much appreciated.
I made a stack overflow question as well, if you want to see more info:
https://stackoverflow.com/questions/51578039/how-to-apply-filmic-tone-mapping-per-pixel