For Hypertrophy: Beyond 5/3/1 or First Book?

Got the book!

Will do BBB 4 x per week.

My main questions are:
How hard to push on the accessory exercises. Leave 2 reps in the tank, or get to max amount without “failing” on the last rep?

On squat day, is the accessory exercise abs; on bench day, it’s a triceps exercise; etc? Or should it be mixed up?

I will clarify my question:
Do the three type of accessories (push, pull, leg/core) have to be done every single training day, or, …
pull accessories get done on push days, core accessories on lower body days, and no idea where to fit push accessories?

If each category of accessory gets 25-50 reps, are we talking about 75-150 reps of total accessory every training day, or just 25-50 total because we only choose one category per training day?

Accessory thread