Playing response and "tone life suck"

I was told that you can redline the input and it's fine. I had a fuzz pedal with no knobs and it always just stayed red unless I lowered clean sense to minus 12. I stopped using it because I didn't want to have to lower clean sense that much for a pedal I only used sometimes. I don't have it anymore but I used this as an example when I asked about it and CK told me it was fine.

Another interesting point, I tried to put into the Kemper my Fulltone OCD, and it sounds terrible, is there any kind of “special” adjustment to do it?

The OCD sounded completely different of a conventional amp.