Electrical – Altium 18 – “Override library primitive” option missing

I'm busy setting up my new install of Altium 18 to match my preferred settings, namely making the default schematic font Consolas (for the purposes of mono spacing and slashed zeroes).

Normally this involves going into Tools -> Preferences -> Schematic -> Defaults screen, and changing all the fonts to the desired one for each primitive. However, since Altium 18 I notice the "override library primitive" checkbox for parameters/designators/values is missing, meaning while I get Consolas as the default font for any new schematic symbols I make, any existing library symbol I use still hangs on to Times New Roman.

Old Altium:

Altium 18:

Any ideas where this checkbox went, or how to emulate the same functionality?