in the summer generally once or twice a month and hit the rang once a week or so.
My thing is the toe of the clus generally is in the air when i address the ball. The heel of the club is basically the only thing touching the ground so I think it could make a decent difference even if it was just psychological.
You are considering a static measurement here. Since everyone will bend the shaft to a certain degree, you need to be fitted for lie angle by actually hitting balls.
And yes, it can make an incredible difference in your game.