OK, our gameplay producer just got back from vacation today so I was able to talk to him about all things stamina.
One interesting tidbit that I wasn't aware of was that permanent stamina and permanent damage (yes there is such a thing) are tuned for a real time 5 minute round, not an accelerated clock. The reason is because we currently don't have a modifier on the tuning for real time vs. accelerated clock. So it had to be tuned for the worst case scenario, which is a full 5 minute round.
I cannot comment on anything about the future of the project, so don't ask me if this can be patched or tuned because I won't be able to answer.
I just thought this information would be of interest to you.