With the recent TMP Board Harmonisation update (https://community.atlassian.com/forums/Jira-articles/Upcoming-Changes-to-Software-Boards-in-Team-Managed-Spaces/ba-p/3240014), the ability to manually clear all Done items from the Kanban board at once ("Clear Now") has been removed. The replacement - a time-based "Hide done work items after X days" setting does not serve the same purpose.

The key distinction: the time-based option clears items individually, based on when each item was moved to Done. Teams that work in batches need all Done items to clear simultaneously - for example, at the end of a weekly cycle - regardless of when each individual item was completed.

Requested behaviour: Restore an on-demand "Clear all Done items now" action on the Kanban board, or alternatively, add a scheduled batch-clearing option (e.g. "Clear all Done items every Monday") that clears the entire Done column at once rather than item-by-item.