Raft.LeaderCh() has two problems: It always returns the same channel and it doesn't prepopulate the channel with the current value. Reconstructing this has proven error prone/impossible.

RegisterObserver() was my next attempt, but the LocalAddress isn't exposed (except by the Transport, which not be available to library code).

I propose to make Raft.LeaderCh() return a new channel per call, and prepopulate that with the current value. That's a slight behavior change, but I don't expect it to break clients.