First of all, if you want to stay behind the ball at the release, having the ball rest at the base of the index finger is a proper feel or position.
Lateral pitch in the thumb can also effect how the ball lays in your hand/palm. Also, not everyone's hand lays on the ball the same, so laying in the palm is a myth or misnomer.
Secondly, the wider the bridge, the more chance or opportunity you have of hurting the tendons in your hand, by splitting your fingers farther apart than natural, normal or necessary.
My thought would be if your are not having issues with your grip, as far as hand or finger pain, as well as performance issues, then you are worrying about unnecessary things.
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Formerly BrunsRico
As posted by Steven..."None other than our esteemed JustRico!!"