Golf Swing: Holding a left flat wrist from the top to impact

Meaning not cupped or bowed

Yesterday i went play and was pulling too many of my shots, the shots sounded pure and I was making good contact, just going straight left. 20 yards left at worst.

I was making a good turn and weight shift, just from the top I was throwing my right shoulder at the ball, thus coming over the top and pulling.

Today i had a range session and concentrated on keeping my left wrist flat from the top and thru impact. I realized that if i held the flat left wrist it was hard to swing over the top. My right shoulder was working downward.

Im wondering if anyone else has used this move to swing on an in-to-out path and how it has effected their power and fluidity.