I have used a slightly open stance for a long time, especially with the irons, and it has worked very well. For some reason it just felt more natural and comfortable.
Hard to tell what works now as my play and practice time have fallen off dramatically.
Getting older and seeking distance, it never made sense to revert to the "draw" setup, with a closed stance. While it does increase the length of your back swing, (the same for a square stance with both feet flared), these setups take me back to my beginners slice, 55 years ago. If you can't clear your hips or your arms lag behind (longer swing / timing issue...............it is going right.
Therefore, I'm sticking with what feels comfortable, open stance, I now need to work on ball position. In the past a miss for me was left. A miss to the right leads me to believe I now have a 2 way miss and -0- trust.
I also believe an open stance helps my bad lower back. Knowing flexibility has been lost, I can feel it in my left side (I'm a righty) not my lower back, with an open stance due to an increased follow through and longer finish. Easy fix by stretching out my left side.
Open stance always eliminates hanging back / swaying / moving off the ball, making good contact impossible even before I start by down swing.