Only HARD states are reliable for notifications, so you shouldn’t have any problem.
For example.
If you have a 3 “Maximum number of check attempts for service” rule for a service:
A service is OK and gets CRITICAL (1st time) - This is SOFT State.
The service’s still CRITITAL (2nd Time) - This is still SOFT state.
The service is CRITICAL (3rd Time) - This is the HARD State -> You notification will be sent.
The service goes OK (Hard State) -> Your notification will be sent.
Cheers,