The microwave I grew up with (70s/80s) had a log-ish scale. The first quarter turn was 0-60s, the second quarter turn got you to 5 mins, etc. I don't remember the exact gradations but I remember it was very easy to get almost any time you wanted.
The log-factor wasn't as severe as I had remembered, but the 0-1m angle is about the same as the 20-25m angle. It was still pretty easy to get 15s, 30s, etc. I'm sure you could do a lot better with modern digital electronics.
I have hated every microwave since.