I understand everything you are saying, and I am always impressed by the reactivity of this community, thank you very much for that.
But I think xruns are not enough, we need to know precisely how the processor reacts to different types of layers. Zynthian is not a big computer and it can’t play like it. And the actual cpu meter is not very understandable.
Like I say mod ui does that.
The cpu percentage could be next to the stereo meter. And yes, as you say, if I have to choose, I prefer to see how the sound reacts.