Mad God’s Overhaul includes several control schemes to choose from.
Kvite
OCU’s default scheme, by Kvitekvist, included in the FUS modlists. Uses vanilla bindings within menus. If you use OCU and haven’t changed your controls, this is what you’re using.
Cangar
Another scheme from the FUS modlists, by Cangar, that leans on VRIK gestures. (There’s no dedicated shout button by default.)
VRIK
The controls are an optional download with VRIK, included in OCU and labeled “VRIK Controller Bindings - Standard” in the SteamVR section of MO2. Shout on 
A, activate on 
Right grip, favorites on 
B. This was the default in earlier beta builds of MGO 4.0.
VR Safe
A close-to-vanilla scheme that shuffles a few actions (sprint, for one) onto inputs that are less likely to collide with mods.
Optimized Oculus
Built for Oculus and Meta Touch controllers. It turns the face buttons into hotkeys and the grips into modifiers (a bit like Shift or Ctrl), opening up a lot of room for mod actions.