Last time I asked my friends which of those extra buttons they used in their microwave, I found it amusing that each one responded with a completely different thing.
HackerNews, do you use any of those extra buttons in your microwave? If so, which ones?
I'd venture to add that a clock config button might also be appreciated by many even if you use it only after power outages and so people don't realize they want it.
My previous microwave had a +30s/start button, power selection, and of course clock setting. And other stuff that I never used. I'd only ever hit start, optionally after power selection. It would instantly start (my current microwave first waits two seconds for more input) and allow me to press it more for more time (my current one rejects adding time). The button was also nice, I don't know how to properly describe it but it was a nice clicky button that extruded, where my current one has a small pressure pad for the quick start button.
I don't feel like I'm asking for much. A start button that actually starts, lets me add time, and that's not tiny and needs a bunch of pressure to register. One proper button. The rest can be crappy, I don't use that most of the time.
I never use power selection myself. (I imagine it's mostly for defrosting?)
Our microwave, an excellent almost-20-year-old Daewoo, has a rotary timer knob (endless turn, digital); a start button that also acts as a +30s button if you haven't used the timer knob beforehand (and that can be cued up multiple times); and a stop button. The buttons are tactile nubs rather than flat buttons. Those are sufficient and perfect for me.
It also has a single button for power selection, another for clock setting, and another button that has something to do with presets or weights or... actually I have no idea. I use the clock button twice a year and after a power outage.
Cooking meat at 1 kW will usually make it explode.