To get noticed, it helps to start a new thread instead of adding to the end of an already existing one.
a bit of information about the RG modes in the Help File
"Apply Gain / Prevent Clipping" is the recommended setting ("This will level out the volume and prevent distortion").
You shouldn't really ever need to select anything else.
If the scanned files are albums, then always select 'Save as Album'.
The Album rg value is a constant for each separate album,
whereas Track mode values can vary slightly.
I prefer to use Album mode for that reason alone, so the whole Album will play at the same volume level.
If you require more info, then this is always a good starting place:
Dither is currently only used for OGG and FLAC formats
More Info here
Personally, I prefer to disable it, heh.