Here is a question

During your backswing do you think you could generate more power by bending your left arm?

I think I could, but I wouldn't want to.

Right now I am hitting my PW about 140 yds. If I get any more power I will need 6 wedges! Most of my power comes from a very late release of the wrists.

From a physics/biomechanics point of view, how would this help?

If you bend your left arm (RH hitter), then you could reduce the distance the clubhead is from the point of rotation (spine). This means that less energy is required to rotate the club head around your body. If you provide the same amount of torque/energy generated by the body's rotation then the angular velocity of the spine-to-elbow could be increased. With the release of the elbow (straighten of left arm) the hand-to-spine angular velocity could be increased. Once the wrist releases then the clubhead-to-spine angular velocity would also be increased. (Increases relative to a straight arm swing.)

However, you would need PGA pro timing to achieve this extra speed and be able to get your clubhead on the correct path.

What you are discribing (bending of left arm) is some what of a variation of "lever power golf" that has been around for ages. Jack Kuykendall resurected it as his version of a simpler golf swing. People who can master this type of swing mechanics can hit the ball just as far, and accurately as those with other types of swings. Nothing wrong with it if done correctly. In this day and age it is not widely taught by instructors. My left arm bends more than it use to, but I think that has lot to do with my own limited flexibility due to the aging process. GJS