I've been trying it myself a bunch now, and it seems like Oculus behavior is different when sleeping more for than a few seconds. After sleeping for around a minute or so, it often has to reobtain tracking and sometimes dumps me to the Oculus menu. This is true for any game not just VZfit. After it brings me back to VZfit its internal orientation has been reset so there's no getting around needing to recenter.
So with all of this in mind, I think increasing your headset sleep time to 15 minutes is still the best solution.
So with all of this in mind, I think increasing your headset sleep time to 15 minutes is still the best solution.