The higher your effort, the lower your volume

Unfortunately, most NHE training programs involve very high repetition volumes (e.g. 3 to 4 sets of 12 repetitions).
For best exercise quality and subsequent muscle-tendon adaptations high activation and forces at extended knee angles are required. Therefore, we strongly recommend to perform on high-quality repetitions by mainly focusing on the range of motion which really hurts.
Hamstring training should emphasize intensity without inducing an excessively accumulating within-set fatigue!

HAM's HELL training usually involves 3 repetitions at high time under tension (~6 s) and highest activation at extended knee angles. Once you gained adequate control, further progression and variation is of course possible!