From customer:

We were wondering if there’s a way we can have an option in the future where we can require a specific Timeline Activity to be submitted as a prerequisite to being able to close out a specific CTA. To elaborate on the use case, we want to instruct CSMs move a certain CTA to status Closed Invalid under specific circumstances. However, we want CSMs to submit a timeline activity explaining why it's invalid before they're able to move the CTA to Closed Invalid.