Hi Sercho!
The patch changes with the pxl live is quite smooth. At a first glance, since the pxl live have 8 banks, each with 4 presets, and I almost use one bank per song with 4 rigs (performance mode on kemper) , i had to figured out how to expand that limitation for playing more than 8 songs. So, from the fact that pxl live can send two simultaneous messages, I set a second message from the last kemper set of slots...at patch 9 of the kemper I reuse bank 1 (a,b,c,d) sending program change in midi channel 2... The only thing I have to do when I finish using the first 8 banks is to change kemper global midi channel to 2...it's a small tweak that allows me to expand up to 16 patches in kemper performance mode...the expression pedals works great on kemper...yo can set then in various ways and whas are awsome and they are independent from pxl live