UM 18.04 systemwide toolbar customization options missing?

I was looking for the toolbar customization settings because I wanted to set it to icons only, like in this printscreen I found online:

I could not find it on MATE Tweak:

so I browsed the user manual looking for it:

but as seen on the printscreen the features described on the manual do not correspond to the availability of those options. Lower in the manual there's what I was looking for but it does not seem to be correct. I wanted to remove the "Back" and "Forward" words from Caja's toolbar, which are totally not needed and just take up precious real estate space:

So where are these options?

Anyone?

Using dconf-editor strangely has no effect, the options can be found there but nothing happens when changes are made, even after logout or restart: