Flames don't show you temperature. You have to learn what the flame level means. You likely learned this so long ago you've forgotten how much work that takes.

Yes. That's what I said. Therefore 3 7-segment LEDs showing the temperature :-)

These old-fashioned things https://en.wikipedia.org/wiki/Seven-segment_display , you know?

One could possibly overengineer it by showing the chosen temperature in red, and the actual temperature in blue, or something.

From personal experience this is unnecessary, as evidenced by water boiling at 100°C, starting to have a few small bubbles/sparkles at 90°C, and none of that at 80°C.

Sorry for misunderstanding you.

Very few people cook with temperature as part of the process (stove top, anyway).

No need to be ;-) These old-fashioned things were 'new' for me, too. About a decade ago, when I had my first induction cooking experience.

But nerd that I am, one of the first things I tried was that bubble check until boiling, and how exact the display is. Since that time I'm considering any other method obsolete. Power in Watts? Useless. Some arbitrarily chosen steps? Useless. Temperature, sight and smell it is!

Actually, I'd argue there's another option, which is the I use 75% of the time with a gas stove and 100% time of with any form of electric stove (except the Samsung-style induction units I mentioned).

Step 1: believe that the controls are consistent and reasonably accurate Step 2: learn what control setting corresponds to what level of heat

The biggest problem with this method is that it can take a while (for me, perhaps on the order of a year or two). At this point, with my current gas range, I don't need to look at the flame - I know that half-way between "medium" and "medium-low" is just what I need for the current cooking task.