Flaps can add stability becasue they increase lift. When they increase lift you reduce the AOA of the wingtip, enabling you to fly slower without tipstalling.

I always use flaps to land my Spitfire. I put in full flaps and then approach steeper witha lower nose than with my other planes but because of the flaps the the plane does not gather too much speed. I find that much safer than coming in low and slow.