Tons of work for the biceps, brachialis, brachioradialis as well as the lower traps and lats in the shortened position. Then transfer those into specific strength with flexed arm hang isometrics with the chin above the bar, building up in duration over time.
What are your thoughts on agonist supersets with something like this? Depending on the strength level of the athlete, doing full repetition chinups/ iso holds at the top immediately followed by a pulldown variation?
Not a big fan of it to be honest. The reason is because if someone is struggling with strength in a chin up, they need more relative strength / neurological work. The pulldown variation post-chin up would just serve to further fatigue the motor pattern at a lower threshold. Fine for hypertrophy, but if performance in the chin up is your goal, then it's not the best option. Think QUALITY over QUANTITY here. After a hard set of chins + ISO holds, it would be far better to take a long rest and prepare for another high output set of chin-ups. Hope that makes sense.