Under Devices > Displays, the "scale option" is no longer present
Compare these two images - the first is taken from Gnome Settings v3.27.92 under a daily build of Ubuntu Budgie 18.04, 32-bit - it has no "scale" option.
The second image is from whichever version of Gnome-settings was present in Ubuntu Budgie 17.10 Beta 1 - I'm sorry I don't know which specific version: https://launchpadlibrarian.net/337255185/IMG_6910.JPG
Thanks, Ken.