OSTexo,
Also if you are so pedant, you better look on his model:


Green Cylinder is perefect one, and it stay behinde his cylinder. As you can see his cylinder is wrong, it is becouse he made that spiral detail constant radius.
To avoid that artifacts that his model has, cylinder must be perfect...
This model have 2 mistakes it has artifacts and it is not perfect cylinder. Also it had messy geometry.
Do not know may be this things are not important for molding :-)