Is it possible to apply the templates present in 5/3/1 Forever for weighted pull ups? How is the percentage calculated? body weight + weight lifted?
531 uses pull ups as assistance, and i think this is the best option. Even if you can do weighted, doing 5x10 with +25 lbs will get you whatever pull ups goals you may have.
That said, if you do this (or weighted dips) as main lifts, using BW + added weight is the way to do it.
Weighted pullups are fine. Take Whatever weight suits you for making 50/100 reps. Don’t be a dick without it (lime doing the hypothetical 25 sets of 1).