You don't do these things because they benefit your boss. (They might happen to, but that's not the point.)

You do them because they benefit you.

Not going to benefit you? There's lots of ways to say no to a back-channel request. Not a back-channel request? Then I guess it's not someone else's job!

There is also the lowercase no, where you say you'd love to do things, but that it has to go through proper channels and get on the roadmap.

Nice reference