Yes, you would move further left.  How much?  Depends on your thumb hinge.  Without being able to read your hand I'd suggest trying 1/4 left first.  I seldom run into anyone that needs more than 1/4 lateral in either direction.  You should not need to change your reverse pitch if you're releasing the ball well now.  The additional left pitch will make it a little easier to get out of the thumb while staying behind the ball, but I wouldn't expect it to be enough to require less reverse.  And I assume you've eliminated the hole being too small, existence of a rough spot in the hole in that area, and insufficient bevel in that area as causes.  --  JohnP