How small preferences in microwave ovens are chosen by the manufacturers

Question

Dealing with several microwave ovens during the lifetime I find that there are at least a couple of peculiarities I'd rather have my way, but they're not usually listed in specifications. I'm not surprised they're not listed, but at least they're set up differently in different models. I would like to inquire whether there is a trend to set those in particular setting by default or it is completely random chosen by engineers/designers at wish. Also any links to known resources discussing small details in microwave ovens UI would be helpful. The features listed as examples below are not related, just two examples I noticed.

• Repeating sound notification that the heating is finished every minute until I open the door. I prefer this not to be included. From four models I dealt with, three had this off, probably a couple had this on.
• Having the rotation phase of the disk aligned to 30 seconds so if you placed a cup with a handle south-east then for any quick heating scenario (30 sec, 1 minute, 1:30, etc) the handle will be at south-east when the heating is ended. I prefer to have such alignment since the unaligned version would might place the handle north-west or similar that is not convenient for removing the cup. Probably two models I met had this alignment, two not.

Answer 1

The answer to "Do microwave manufacturers make up product decisions on their own, or do they follow industry trends?" is a clear "it depends".

There are some definitive trends manufacturers follow to make a product desirable. Desireable doesn't mean practical, it just means that it sounds like it'd be amazing to have before you buy it. Posy has a video on a very desirable CD player that's worth checking out for more info on this. In the context of kitchen stuff, a more recent example is the introduction of touchscreens and more generally capacitive buttons over physical knobs. Not practical at all because they don't work when wet, but damn do they look modern. Other example include "smart", "cloud" and "AI".

The features you describe however aren't really bound by these trends. The "VP of microwaves" at Samsung won't be demanding these sort of UX micro-improvements, instead it'll be up to the designers and engineers to figure this out. And here there is no definitive answer to the question, unless you were to ask the people themselves.

Holding a finger in the air, I'd speculate that some of them are attempts to solve real problems (like "people forget their meals in the microwave because they didn't hear the initial beep from the kitchen") while others aren't design decisions at all, but rather depend on what kind of motor is cheapest/easiest to source which just happens to make things sync up.