I don't own a Rample, but from the fact that the stereo sample support was added later, and there is no mention of pan (only level) in the manual, I'm guessing it's mono.
Lugia's rebuild, as usual, is ambitious and gives much food for thought. I always learn a lot from these, even for situations that I'm unlikely to find myself in. I will point out that the Klawis Twin Waves is digital, replacing the Nano Ona, which is analog, if that makes a difference (it may not).