Seems so - it builds in the verification infrastructure requirement, making it dead simple to change whether it is opt in or opt out at any time. It's actually

Seems so - it builds in the verification infrastructure requirement, making it dead simple to change whether it is opt in or opt out at any time. It's actually pretty hard not to have a change be part of a slippery slope. It requires including blocks for further behavior as any subset implementation is hard to sell as not being a slippery slope path otherwise.