Can you post a screen shot of the histogram in LC of the gain files you are shooting?
In your old post you state you open 2 stops and pop a strobe at the lens. I'd be surprised if that gave you consistent usable gain files.
I've shot gain files using a strobe shot at the lens and if I'm not careful with the exposure it can give strange results when applied.
I've never had to use a gain of more than 50%, usually much less is more than adequate.