Did you try to hit CTRL+Numpad 2 as a test, when you are inside a VR session?
For me it’s 45FPS ASW OFF obviously (Rift CV1), and those shortcut work fine, I can see it immediately when monitoring fps. It should be 40fps ASW OFF for you AFAIK.
For the record (for my CV1):
CTRL+KP1 - Disable ASW and USE ATW
CTRL+KP2 - Force apps to 45hz, DISABLE ASW
CTRL+KP3 - Force apps to 45hz, ENABLE ASW
CTRL+KP4 - Enable ASW to operate automatically