AssumeReachable 1 on a relay doesn't make it publish quickly
According to the man page for AssumeReachable,
If set to 1, don’t do self-reachability testing; just upload your server descriptor immediately.
But sometime between then and now, perhaps when we messed with the "we don't publish until dirport is reachable too" logic, we lost that 'immediately' property.
It looks like now we don't do some of the checks, and also we don't publish immediately, and then we end up publishing "after a while" when some other condition triggers to consider publishing.
I'm guessing the fix could be as simple as "when we bootstrap to 100%, check if assumereachable, and if so trigger a publish then."