Had some trouble finding good momentary footswitches for the Kemper that worked well and were convenient, so I've spent the last few weeks working on a few prototypes. Found a momentary footswitch that works well, and is robust. These plug into the Pedal 1 and Pedal 2 jacks. If you used controller pedals on Pedal 1 and/or Pedal 2, they can also be plugged into a midi pedalboard directly. I did that with my Ground Control Pro. It also allows you to set up pedals for each rig/midi preset.
Details are on my webpage. I'm offering four different footswitches - 2 two button and 2 four button. Only difference is either hard wired or with 1/4" TRS/Stereo jacks so you can use your own cables. Enclosures are powder coated, very robust and work great. The four button hard wired has one cable with 4 conductors, so you don't have to mess with two stereo cables.
I've used mine with MIDI at the same time, you can either extend the usefulness of your MIDI footswitch - there's a full list of what you can control on my page again - or carry one as a backup. If your MIDI footswitch acts up, you can use one of these to at least get basic functionality - changing rigs up/down and secondary functions - I'd set up a volume boost for leads and possibly a virtual preamp pedal pushing the amp for a little more gain.
Plus the four button switch fits in the back of the non powered Kempers.
It goes without saying, but I don't work for Kemper, I'm just a fan coming up with some solutions for my personal use I'm offering to the community.