The larger offset pill just extends the range of adjustment. The dot refers to the degree change of caster when both eccentrics are used (3 dot pill on both top and bottom allows up to 3 degrees of added or removed caster).
Personally I like having the 1 and 2 dot pills for finer adjustment within the OEM range. I find I almost never need more than max caster with the two 3 dot OEM pills, so it’s nice to have the two smaller pills to fine tune caster without affecting camber.
One of the nice things about the full range of pills is that it really lets you define and isolate caster and camber changes. Use the top pill solely for camber along the X axis and you have 11 camber settings at your disposal without affecting caster. And on the flip side staying along the Y axis on the bottom pill you have 11 caster settings that won’t affect camber.
Basically it allows you to think of camber changes in more of a linear fashion than dynamically. A click or two of camber also affects caster when using the stock pills.
Nice tool to have in the toolbox though. Particularly if you enjoy the testing, tinkering and tuning portion of the sport.