Comments
Indeed, this is inconsistent. It is also not possible to adjust the actions that can appear on factboxes through customization, which is something we're really missing since leaving the RTC. We should be able to surface and hide factboxes at-will.
Category: General
You can remove a Fackbox from the page in design but you cannot add it back again, which some users see as being inconsistent.
Category: General

Business Central Team (administrator)
Good news! We released the ability to bring back factboxes as part of the functionality in Unhide Parts on a Page.