+1 to this. We have a couple use cases:

We've expanded the Due Date functionality of Task-Type tickets to be used across various other types of tickets by creating a hidden custom "revisit date" date field. Once the ticket is revisited, the revisit date remains on the ticket. It should be cleared out if a ticket doesn't need to be revisited.

We've also created an "agent-deemed solved" date field to compensate for the delayed resolution time caused by bump-bump-solves (when an agent puts a ticket on pending and BBS solves the ticket out, we use this date as the solved date). We need this field to be cleared out if a ticket re-opens and is no longer solved.

Although we can make configurations to have ticket flows ignore the fields, the bigger problem is around data and reporting.