Hi Coach.
I realize loss of performance when I put rep style variation inside the same workout session. Seems like my brain are not prepared for the second method.
EX: When I do heavy compounds (fewer reps) at the begining I don’t perform well isolation/ high reps exercises. There’s some logic? Or is it maybe my personal preference?
Thanks for your attention.
You are very correct. That’s why my newer programs and the approach I use with my clients is unimodal most of the time (one type of method per day).
What you experienced is most common with people with low acetylcholine and/or low serotonin. This makes them less effective at adapting to various tasks on the fly.
Plus, the more different elements there are in a workout, the more demanding it is on the nervous system. This can not only explain the lower performance but also the fact that it can be much harder to recover from.
Very interesting.
But now a have a “problem” 
I was convinced I’m type 1B (high acetylcholine).
But the situations I describe above indicates I’m 1A, right?
I should start shorter intense workouts.
Nah, it could be low serotonin due to other issues. Or lack of acetylcholine due to low choline intake in the diet