Please correct me if wrong, but if I understand correctly, a scene might be B,C,D,Mod, Delay on as a scene assigned as a scene to any one switch. Not a toggle of what those stomps/effects were, just those on and others off. Creating multiple scenes along that line would give you a lot of combinations off of a single switch click. You might be able to do something similar with a morph, but you'd have to have all the effects you wanted on and rely on them having a mix parameter.
Understood that we currently can't switch any of the assigned 8 slots to a different effect, but if the scenes could not only turn on specific combinations, but maybe have their own morph-like parameters stored in the scene, that would give you quite a few possible combinations. Like Scene 1 with no Kemper drive but other effects on. Scene 3 with just Kemper drive and reverb but low gain. Scene 3 with Kemper drive high gain and longer delay, and so on.
I don't have the Kemper footswitch, but I'm thinking this isn't currently possible.