Take care when removing a field from a layout: Craft stores field content using each instance’s UID. Re-adding a field (whether or not it uses the same handle) will give it a new UID, meaning it will no longer be associated with existing content! By relegating these changes to a development environment, your live data is typically insulated from major loss—if you do mistakenly remove a field, you can always roll back the corresponding project config changes via git before deploying. Moving field layout elements between tabs, however, is nondestructive.