low gain verses high gain

I'm looking for information to verify what I've found using these two settings.

Settings:
sensitivity 29 "low gain setting"
disc 5

What happens to the low gain settings if you drop the discrimination to 0?

Now observe the pinpoint mode when in either the low gain and disc at 5 verses low gain and disc 0?

Do you think that dropping disc to 0 counter acts the low gain setting?

I've never been in a situation that would require such low settings.....but I'm sure there would be a slight performance gain by dropping Disc from '5' to '4' (or lower).