I use Timers all the time, especially in the kitchen. I mostly trigger a timer with Siri on my watch. Yesterday I set a timer so the meal I was making could cook for 40 minutes before I added more ingredients.
Forgetting that, and after doing some cleanup, I then made a cup of tea and set a timer for 3 minutes for the tea to steep.
That second timer simply obliterated the first, with no warning. Annoying!
The behaviour I'd expect would be some feedback pointing out I already have a timer with x-minutes to run, should this new timer replace that?
Best of all, of course, would be to be able to run multiple timers on the same device concurrently.