My mouse gestures "Sketch" ring is set up with common sketch commands AND the Extrude/Cut-Extrude icons. Now, I open a new sketch and sketch some geometry. Try two closed loops (circles, rects, or other islands). Then, slide over to the Cut-Extrude icon on the ring. You'd expect it to grab all the geometry and cut all islands. But it doesn't. It asks you for a selection or takes the current selection only. Hmmm. Next it really deviates from the work flow, because it creates a new sketch with no relations back to the original. What? Yep, you started sketching in Sketch(n). When you complete this operation you really cut using Sketch(n+1) with no continuity back to Sketch(n).
I'm about to abandon that work flow, but I thought it was interesting. Try it out.