I stopped 8:12, immediately after I stopped 8.12. 8:11 popped up and started ringing again. So I stopped 8:11 too.
8:10 was supposed to snooze at 8:15, so it did. Nothing strange, all good. This time instead of snooze, I did nothing, after the hardcoded 60 seconds it turned off. At 8:20 it started to ring again, however, the time that was displayed on the alarm was 8:15, but it was 8:20 in real-time.
Also small-feature request: Prohibit blanking of the screen while an alarm is actively ringing. It does turn the screen on/unlocks but it uses the default time-out value. If one wants to stop/snooze, after 30 seconds (my timeout-value), one needs to reach for the unlockkey first. When I am sleepy, that's too hard for me. It vaguely remember the default plugin already did it, but I can be wrong as I didn't use the alarm for a long time after it failed one day