I have been using the alternative input on the back of my kemper rack fine for a long time.
I run a mix of different external pedals as my front-end, changing them regularly, and have never had any issues with noise until recently.
I have a couple pedals that when they are in my chain there will always be excessive noise, making them unusable. If I move from the rear alternative input to the front of the kemper, then the problem goes away.
Anyone experienced this issue or know what the official word on this might be?