+1 on that, I would love that as well.
Also I think that Pan Spread could work with Unison, combined with Slop and the voices being different anyway it might beef up the spatiality in a nice way.
Another more dubious one that I would like to tinker with, one Pan Spread mode to split the lower 2 octaves on the left channel and the top 2 on the right channel, allowing separate processing of left / right hand (not quite a split keyboard mode but at least doable by the current hardware?).