Would be cool if there was a global volume boost that could be set. It wouldn't even have to take up a block. Rather, it could be assigned a midi # and would automatically bump up all selected outputs by a certain number of decibels. The limitation would be if the volume hits the ceiling, but in most cases we're not setting any of the Kemper's outputs to max anyhow, at least I'm not. Thus engaging it would boost all the outputs by six decibels, if you'd like. Yes, I'm aware that you can place such a boost within a preset, but then if you decide that if your boost in general is too much, you'd have to go and edit each and every Rig. Globally, you could do this once without affecting any of your rigs. Plus it would free up one of the slots for something else. My T.C electronic G system had this feature and it was really useful.
Personally, I often don't want a high gain Rig for a lead, I just want to boost the volume of the current Rig I'm playing without increasing gain, just to jump out of the live mix. It would be nice if I could just adjust this globally at a gig and eat up one of my four post rig slots to do so. Since many of my rigs use some post EQ, I use a touch of reverb in all my rigs, usually want some delay to engage, I only have one slot left, which I'd prefer to use for some sort of modulation.