Bulk Deactivate Events (on a case) Block
The Bulk Deactivate Events block allows you to select from multiple future events on a case to mark inactive. Marking events as inactive will mean that they will no longer appear on the calendar or other list views filtered to show active events by default. They will, however, still appear by default on the events list view on the case itself.
You can add this block to a closing form or to its own auxiliary process and include an instruction for your users if you'd like.
There are configuration options to include tasks and deadlines.