Is your feature request related to a problem? Please describe.
I was implementing an API on top of V n a, and needed to drop the whole V.

Describe the solution you'd like

instance Consumable a => Consumable (V n a) where
  ...
instance Dupable a => Dupable (V n a) where
  ...

These are just tricky enough that it seems worth building them in house, and the unsafe implementation is probably faster than what can be done through the public API.

Describe alternatives you've considered

orphan instances, mostly.