Specifically, which penalties can you use it on, or not.
Adept Centering
allows you to reduce negative dice pool modifiers to
Physical and Combat skills (such as modifiers from adverse
conditions)
OK, so adverse conditions is just listed as an example, but that lets us know we could use it on penalties such as glare, lowlight, smoke, etc. Surely slippery floors, a rocking ship deck, all that too.
Can you use it for the shooting blind (-6) penalty? That's just the same as complete darkness, an adverse condition.
Now, it's not like it can be used only for adverse penalties, that's just an example.
Can you use it on range penalties? If not, why not? That's not exactly a world ending bonus, but it means with just a couple levels of initiation, you don't really need a ranged scope most of the time, at all.
Here's the big one that occurred to me:
Can you use it on Called Shot penalties? If so, whoa. Even just initiate 2 and you are suddenly thinking called shots are no big deal, using them all the time.