All I know, is that if one is running 25+ psi of boost and the fuel hiccups, one has a very expensive mess left under the hood.
I don't know exactly what you mean by knock threshhold as I have always run a couple of percent more fuel at a minimum than what testing showed I could run without detonation as I have found it makes minimal difference in performance to be a little rich.
I also know that fuel quality varies as do ambient conditions and I like to stay away from all the possible lines that I can think of. Having a management system that tries to save the engine seems like commonsense to me if something goes wrong.
Having the ability to monitor fuel pressure and alert me early is better than finding out that the pump is going away too late.
I distinguish between warnings and tuning.