I have cleats on the 17 to allow me to do "Other things" without having to stand on the Spi sheet to keep it drawing.

I set the cleats way forward so it is very much an "Active decision" to cleat the sheet and so I don't get caught out by accidental cleat-ups.

I use them when (usually in light wind) mucking around with mainsheet tension, traveller position or Plate position. I Always keep the Spi sheet as much to hand as possible to allow a quick sheet in if need be in emergancies along with a rapid bear off.

I've toying with the idea of putting a couple of footstaps on the tiller bar / extension to allow me to steer with my feet as well so I have both hands free for longer (always scary letting go of the tiller extension).