Have you ever looked at Non? It has a recording mode that is a lot like what you described if I understand you right. Development is kind of moribund but that can be an advantage in some ways.
Unfortunately it requires Jack, which for me has always been a source of frustration. I can get very low latencies and excellent stability using Alsa alone, so don't feel the need to change. Unfortunately as much as Jack is incredibly powerful, its UI to organize and connect stuff together is an example of how terrible usability choices can ruin an otherwise great software.
