Ability to use more fields within Reminder Notification Trigger

[#1]

It would be great to be able to use more than the basic "Qualifying Period" triggers when sending email notifications. This would allow for greater flexibility when setting up these reminders.

Our use case is:

1. A team member submits an issue to record some data for record keeping purposes
2. A custom form field is used to record a "in-market" date.
3. An email reminder needs to be sent to the user who submitted the issue to remind them to ensure that their product is actually in-market and to update the issue with any relevant details.
4. Triggers for the reminder notification would be:
   1. If $$TODAY is greater than the date specified in the Custom form field; AND
   2. If the Queue matches a specific ID; AND
   3. The issue is NOT completed.