Seems like there was always an XMarks section in Firefox>Menu Bar>Tools at least in Linux version of Firefox now in Firefox 56 there isn't. Is this intentional? I know in OpenMandriva our devs had a heck of a time building FF 56 till we got a handle on Rust/Cargo. Don't know if that's a factor or if this is a work in progress or something is missing in OpenMandriva's build of FF 56. Anyway I would prefer to have the entries in Firefox>Menu Bar>Tools back.
And yes I know how to put the Icon in the menu bar or elsewhere that just isn't my preference.