Why do I need to calculate a value for the permissions in Double Post Merge and not just insert the minutes I want?

Since permissions are prioritized highest to lowest, your permissions would not work as expected if you just enter the minutes you like posts to be merged or threads to be bumped. This is why we changed the permission system and wat you do calculate a value.
See the documentation for more details:
https://wmtech.net/threads/wmtech-double-post-merge-new-permission-settings-manual.53/