I haven't seen any machine where the sensor dry worked.

When I bought my house it came with a dryer and indeed the sensory dry never seemed to work.

A year later, I decided to look into it. It occurred to me that there should be an exhaust somewhere on the exterior of the house where the dryer is blowing air out of. I went looking for it, and couldn't find it! This was crazy.

After a lot of searching, I finally found it - the previous owner(s) had blocked the vents - they were covered. I removed the block, and air could flow freely again.

And suddenly the sensor dry worked perfectly.

If yours is not working, do some debugging.

Woah! That sounds really dangerous! I've had to get properly ventilated dryer vents cleaned out a few times. I've been told they can cause fires if they get too clogged.

On the other hand, I've had a dryer that didn't have a sensor and the timed dry was hard to get right. You could destroy clothes because they would go past dry to 400 degree annihilate.

What you really want is "sensor dry + 10 minutes" or some other offset.

we really need open appliances (with some safety features)

I have a bosch one and yeah when it stops most clothes are damp feeling. If you trust it and hang it up it's actually quite ok. I just set it to go for 90mins and everything's dry. I do really like it though, the filters are so good I mix all my clothes in one wash and i don't see any lint.