Is there a console command for manually changing User Interface Scale?

The title explains it all.

None of the sliders in the menu work for me at all, so I’m having to change everything via console commands, I can’t seem to find this one though.

I’ve never seen anything about a console command for it, but I’m guessing there would be.

Have you had a guess at it? I would try -
ui.scale (value)
userinterface.scale (value)
interface.scale (value)

If all of them fail, which they most likely will, you can always just open up the cfg file and manually change the values in there.