Currently, there's no way (natively) to have an FX channel which downtunes/uptunes what's sent to it. The only option is pitch shifting each track individually, but that makes things complex for handling multiple tracks, or just adding a small amount of pitch-shifted signal in the background (e.g. for thickening).
In Pro Tools, this is possible, because there's a pitch shifting plug-in that can be put onto an FX channel. It would be great to see a basic pitch shifting plug-in for S1 too; nothing complex, just the same basic pitch-shift option which already exists for tracks. It's not like the technology isn't there in S1 already.