With an extended FP, you can run a reduced mainspring - this provides a lighter pull - which is very important in DA. You need the extended FP to make up for the reduced impact on the primer. If you run a full strength mainspring with an extended FP, you risk primer piercing which is a bad thing.
That makes sense. I carry mine cocked and locked, so I guess that I wouldn’t benefit much, but thanks for the information. I know others have the decocker model or thumb down the hammer to carry with the safety off.