I would like to suggest a "Lock Editing" option similar to the "Delete prevention" option on ArcGIS Online items. This is to prevent accidental modification of the item (e.g. web map, web app) by others in the organisation that have the correct permissions.
For example, we have several web apps and associated web maps that are used as live applications by others in the organisation. However, it is relatively easy for someone with the correct permissions to open the item (especially web maps in Map Viewer) and accidentally edit and then save. This change then affects the live application(s).
Having a "Lock Editing" option on the item, would prevent a user (even with the correct permissions) from editing the item and saving, without first disabling the "Lock Editing" option. This would work in a similar way to "Delete Prevention", forcing the user to make a concious decision to edit the item.
For example:
Note that this is separate from turning on/off editing of feature layers. This is to prevent editing of the ArcGIS Online item itself and is probably most applicable to web maps and apps, but could equally be applied to item details/metadata of feature layers and/or editing of feature layer views etc.