High Frequency Program vs CNS Recovery

CT I will keep it short. With programs such as Best Damn Natty and other high frequency routines, the primary argument I have heard against them is that although the individual muscles have days off (example push muscles M-W-F, pull T-TH-SA) you are taxing the same CNS everyday Mon-Sat. Some trainers have stated that training till failure, training with a high % of your 1RM, set extenders and focusing on the negative reps are very taxing in the CNS. I assume the low volume in each session would be a mitigating factor. Can you please share your thoughts.

Frequency / Volume / Intensity are elements that need to be adjusted when you plan a program. When one goes up the others go down.

Everything that is challenging stresses the nervous system. But training that is not stress it to some extent does not lead to significant changes.