The email I got for this just now says this, so hopefully they fixed the noise. I don't see the verbage about the noise floor on the website.
"The Seed3 sports a new audio codec with crystal clear audio. Up to 32-bit, 192kHz processing and an unbelievably low noise floor (-120 db)."
Side-chaining is when a signal output controls a parameter of another effect. So in Feral's example the autowah and compressor would have to have a separate input for the sidechain trigger that routes to one of those particular parameters, which in the case of the autowah would be the split dry...