I just read a earlier post about your recovery and feelings when you had several CNS days and decided tu split your training. After my recent experience (long story) I feel more or less the same symptoms when I exceed some of my workouts. I'm learning to listen my body more and more.
For instance I change my program this week. I went from main lifts 3-5 double progression and regular sets on assistance exercises to a 5-3-2-1 and some mechanical drop sets. I specially felt my worst when I train legs. My HRV drops, sleep patterns altered, I hold more water, my BP increases, excessive urination at night, but the workout is awesome. and the point is that, when my leg workout is awesome my body breaks.
For this reason I think your thoughts on split the CNS days and Hypertrophy days have opened a new approach to design my workouts.
How did you manage supplements of another tools for improving such condition and adapt better and better to the stress response and recovery? both medium and long term tricks to increase your performance and reach goals.