I have Firefox for Mac, PC and iOS synced on Firefox accounts. On the Mac and PC, I don’t even have the Library button on my toolbar so I never have my recent bookmarks exposed. On Firefox iOS, the only way I know to access my bookmarks is tapping the “hamburger” in the lower right, then tapping “Your Library”, which brings up the Bookmarks menu. I can’t access Bookmarks without exposing my recent bookmarks, which are individually displayed on the top level of Bookmarks. This does not happen in the Bookmarks menu in either the PC or Mac versions of Firefox.
This is an unacceptable lapse of user security in a situation where people are very likely to be looking over your shoulder. Firefox lets us turn off search suggestions for a reason; that same reason applies here.
If there was a Recent Bookmarks folder in Bookmarks, that would be fine. Even better would be an option to not keep a list of recent bookmarks.