I am checking out your findings here....for me, based on the guitar/pick ups/cable - I do get that "noise" coming after a note, but it is definitely a hum/noise from the chain -- not the Kemper. Same thing happens when using a tube amp. But I am interesting in the "definition" parameter.
FWIW - when I use a guitar with noiseless pickups (Joe Barden), a high quality cable (George L), I get no noise whatsoever after hit a high note and holding it. Guitar tone is complex beast!