The better your alignment (a the classical sence) the more likely you are to sap your arm.
You can control most of it by either changing your grip to the Howard Hill style of coming in slightly from the side,or by opening your stance a little.
I have a slightly beyond closed stance for most shooting situations,but If I want to clear my jacket arm,all I do is put my back foot around 6" further forward of where it would normaly be.
This opens the stance and as a result my bow string clears my arm more.
Open or closed,think of it like a door but base it on your back foot,square an the door is closed,slightly forward an the door is slightly open.
My usual stance,the back foot is behind the line of my front foot,,,slammed through the door frame ;^)