Rewind and string length

Is there a recommended minimum string length for doing Rewind? I find that my usual string length doesn’t leave enough to comfortably land the Double Brother, never mind the Triple.

My usual string length isn’t that short, I don’t think. If I let the yoyo touch the ground, my throwing hand, when held parallel to the ground, is about an inch above my belly button (I’m about 5’8”, btw).

You are a a couple inches taller than me, so I would assume our strings are about the same length based on what you described. I would say that should be plenty of string. You can always try a bit more though and see if that helps.