I'd have to know the specifics of the switch box to be 100% certain, but even without that I think it's reasonably to call it 99+% assured that the switcher doesn't offer any D/A conversion.

Receivers often provide composite/s-video transcoding, but I highly doubt that a switch box will do that. I'd expect to have to run composite video and stereo analog through the switch box and into the LeapFrog if those are the only inputs it supports.