You do not need to use an execution step to send the notification. Set up the notification on the decision step with the timeout with the notification event set to Specific Error and the Error set to timeout.
You will need to calculate the amount of time you want to wait and store the result in a hidden token on the request. This timer can be calculated with Oracle time functions if necessary. You can use minutes, hours or days, depending on how finely you want to control when the timer expires. Keep in mind that the timer will expire only if the step remains active for the whole timeout period.
We have addressed this requirement by implementing a custom Oracle procedure to check each relevant request and to send the appropriate notification where applicable (for example after a number of days after a specific status change).
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