Those are good points! I can imagine positive feedback to be desirable in some situations and to some extent–a musician’s amplifier needs to have some positive feedback to amplify the frequencies they care about, for instance, but likely also needs some negative to cancel out frequencies they don’t want to amplify, either in the amplifier itself or in the sound booth. Or maybe for some chemical processes, where you always want to make more of product X, and you’re just adjusting the positive feedback to keep the production of X at a certain range of acceptable rates. It all comes down to the math and the desired output! My areas of work are mainly related to areas where negative feedback is desired, but it’s really very context-specific.

As for “more optimal,” I think I picked up the habit of avoiding that phrase due to grad school being my life for so long. A lot of my cohort was very controls-focused in their research, and several of the controls profs would correct presenting/proposing/defending students if they used that phrase, so we got used to either avoiding the phrase entirely or jokingly pointing it out if a fellow student said it. But in my full-time job now, things are much more relaxed with respect to that sort of thing. Maybe in a few years, I won’t hear those profs’ “can you tell me what you mean by ‘more optimal?’” didactic questions in my head when I encounter the phrase 🤣 And yeah, exponential growth is another good example! It’s clear in the colloquial sense, but my engineer-brain still thinks “wait a minute…” when I hear it!