It's important to distinguish between the 8x small sliders which work as I described in my previous post and the single larger slider alongside of them. The latter "can" be manually assigned (and will stay assigned till you change it again) but only to a limited no. of functions. You're presented with various volume combinations to select from and can only select any one at a time from Mic, Keyboard, Harmony, Song, Style, Multipad, Audio Play, or Mic Reverb or VH balance. Other properties are not available.
John