"The tools only need adjusting when reground or if I need more overhang"
Do you make no adjustment for top rake? For example if I were using a similar type of bar on brass I would rotate it so it had zero top rake, if I were using the same baron say aluminium I would rotate it to give some positive rake. This will affect the height of the tip which cannot be altered by rotating without altering the rake angle.
To me as soon as you use your setting block you will be affecting the rake of the tool