My advice is to use the SLOs and repeat the event.
Suppose you have a ticket set to status "Pending". What you can do is:
-Create a site defined condition macro in which the condition is to check if status = Pending, it will return "true"
-Create the event so that the above condition is in place and on True, send email. On False, do nothing.
-on the given SLO, have it run at whatever interval of time you want.
In the above example, the moment the status is set to a value other than Pending, the event will find as condition false and do nothing further.
I believe that on False, you could run another action macro that stops the Service Type event perhaps?