Persistent timers are currently optional and not the default. I think it would make sense to make them the default and have the old single alert timer be optional (or even remove the option completely).
FYI, I found a bug just now where "persistent" timers sometimes do not get stopped, and Ulauncher must be restarted to stop the alerts. I will work on a fix ASAP (hopefully later today).
Features added
Persistent timers are currently optional and not the default. I think it would make sense to make them the default and have the old single alert timer be optional (or even remove the option completely).
Tests were added for all new features.