Personally I don’t see a conflict here. The nervous system works in cycles, sympathetic and parasympathetic. That happens even when when your NS is chronically overstimulated, it just has a distorted baseline, compressed parasympathetic and sympathetic range, and impaired recovery. Running Regen won’t just permanently lock you in parasympathetic mode, and Beast won’t permanently lock you into sympathetic mode - the way I see this working is Regen will help activate and sustain the parasympathetic, allowing deeper rest and recovery, which then allows an improved sympathetic response (e.g. during a workout), followed by improved rest and recovery afterwards. So I see Regen as improving the effectiveness of Beast.
At least that’s my theory. And since we’re still waiting for Health Protocol (whyyyyyy?!), gonna pause Paragon for a bit and replace with a Beast custom to give this combo a try.