What if Sony advertises that VR needs extra power to run, so every VR unit has extra computing power included. If you dont use VR but have the device plugged in, the extra computing power can be used by the game currently running if it needs it.
So if Witcher 3 or Fallout 4 cant keep 30 fps constantly, the extra power will be used to offload some work so that the main process can target constant 30 pr 60fps.
Of course i have no idea if that can realistically work in the first place as a computing power addon.
But most owners of the PS4 wont be angry because they can just buy the extra unit.
Of course some will say that the Devs will now target their specs with the new power unit in mind.
lets look at it that way: When Fallout or Witcher drop below 20 to 15 fps in certain areas or situations. You have to suck it up as part of the game or wait until a patch crunches some 5 to 10 fps out of the code.
But if the vr power unit is a thing an you read somewhere that you get a constant 30 with the ps4vr power unit plugged in, you would be angry at the devs because they targeted the vr specs and not the main ps4 specs.