I tested it on my default install by enabling lowgfx through CCSM.
It did switch off all transparency effects. Also there are no preview animations in Dash but I still have fade in and fade out animation for showing windows (Super+W).
In my testing using virtual machine that animation was disabled so I guess it works as intended. Also in virtual machine I can't enable workspaces.
I tested it on my default install by enabling lowgfx through CCSM.
It did switch off all transparency effects. Also there are no preview animations in Dash but I still have fade in and fade out animation for showing windows (Super+W).
In my testing using virtual machine that animation was disabled so I guess it works as intended. Also in virtual machine I can't enable workspaces.