I believe SB code uses fixed width font when viewing in MDP. i don't recommend changing it.
I use BBEdit to write and view code on my mac. It has a free version ideal for SB coding and easy to use. It is a real code editor, but for SB I just use it to type and align code, then I use SB to find and correct errors.
It is extremely convenient and provides easy multi-line indenting to match SB code when inserted in MDP. Easy to print with line numbers and markup. Easy to copy and paste into MDP SB Rules and vice-versa. Notes and Word doesn't provide multi-line code formatting. Using tabs one line at a time is not natural for coding.
Sample code straight from BBEdit:
IF M0 == F0 7D 01 00 # Received Master General LCD message
MAT J0 = 0
MAT J1 = 0
MAT J2 = 0
IF MA == 30-39 # Stepper LCD valid value
MAT J0 = MB - 30 # J0 is units value
MAT J1 = J0 * A # J1 is tens value
IF MB ==30-39 # stepper value > 9
MAT J2 = MB - 30
MAT J2 = J1 + J2 # tens + units
ELSE # stepper value < 10
MAT J2 = J0
SND B8 09 J5 #CC 9 09 J5 = Mast Gen digit value (1 to 99)