But actually everything changes the env, so this proposal is going to save us: 
A) Quite some typing in the main pattern match
B) One explicit env per method 

At a cost of: 
C) Writing `implicit` everywhere
D) Having to provide multiple argument lists to context-carrying methods
E) An introduced potential for confusion if someone actually forgets to provide an explicit environment where it's necessary

I think C and E don't justify savings just in the main pattern match for now. Let's see how the codebase evolves, and maybe later we can revisit this?