Yeah we’ll see 
I keep it in mind in every playing session. Maybe if I lose some weight my fat thighs won’t make the shamisen be so far away from my body… 
Where your arm is on top of the doukake is going to constantly shift slightly and you will adjust as you play. I went over this and realized it with Anne just last week when she asked me how to properly hold it.
The important part is to maintain the balance and that somewhat 45 degree angle so that you don’t have the instrument really wanting to fall to the side.