I ran my SP-01 with a dovetail red dot, and it felt "wonky," it added weight to the slide, which in turn might have contributed to my feeding issues. I am saying "might" as I have never gotten to the root cause of the problem. Also, the weight was added to the top of the slide, which made it tilt up more than usual during the recoil movement
Later, I sent it in for a slide cut and a few cuts to lighten the slide and offset the weight of the red dot. Since then, I've been enjoying the pistol and zero feeding issues.