I frequently have workflows that require tasks to be due by x number of days after an indexed date.
The problem is I can only set the reminder date by a variable, which requires me to hardcode the due date after a reminder date.

I have a situation where a reminder date is 1 week before a due date, and the due date should be 30 days after a date index field.

If the document is stored the day before the task needs to be due, the reminder date defaults to the following day (since a reminder cannot be set to a past date), which shifts the due date to a week after it's actually due.

The best fix would be to allow due dates set by variables.
This would also benefit workflows that have multiple tasks that all need to be done by the same due date.