jhdcs

While I'm not @nnmm, I would like to add in my two cents, if they would help. All three should be implemented, eventually, however there are perhaps different priorities for...

May I ask why you're creating a subscriber after spinning the node? This feels like an unusual design pattern to me - usually your node has all desired/needed subscribers/publishers/clients/services already...

> Creating subscribers on the fly will work after [#446](https://github.com/ros2-rust/ros2_rust/pull/446) is merged, but that's currently blocked on [#430](https://github.com/ros2-rust/ros2_rust/pull/430) getting approved. I knew I was forgetting about something. My apologies. Review...

In reference to your discussion points, I think that having timers use `Duration` would be valuable.