The general tolerances for most golf club manufacturers is to allow for plus or minus 1/2 of a degree for the loft and for the lie.
I agree that a 1/2 of a degree off in lie is not a big deal. A lie that of a six iron is off by 1/2 a degree too flat will produce a push, causing your shot to be approximately 5 feet right of target. ( Note 1 degree off on average players #6 iron lie will cause the ball to be approximately 10 feet offline for an average mens club head speed according to Titleist) . If your lie is 1/2 a degree too upright you will pull the ball ever so slightly to the left of your target. Not to bad so far.
The loft however can change the relationship of how the shaft “enters the head”. If the hosel is out of alignment or bowed, it can affect the clubs “balance”. This balance has a direct effect on where you strike the ball on the club-face.
My Hanging Method can fix that !
The Club Whisperer