WIP - Do a backoff of waits for operations

Want feedback on approach - was thinking 0.1s, 0.3s, 1s, 3s, 9s
or similar

In practice create operations will probably settle into a distribution 
between 10ms and a few hundred ms, and when #353 is altered the longest
ops will get much shorter.  So in practice we'd want to catch 50% of the
op completions in 1 cycle, 75% in the next, etc.