Couldn’t find any reference to specific joint angles but I guess its because they haven’t identified the need. I’m thinking that this may represent a window into improving eccentric strength needed with more upright running where knee bend is smaller.
The concept of drop landings in this respect would be similar to an Olympic lift with a little jump or hop when executing the catch as kindly demonstrated by Nick in a video post previously. However by using a depth jump (without the rebound) the fall would likely preactivate muscles to a far greater extent than the OL version. This would no doubt be more beneficial to sprinting. Still I doubt whether the forces of either version would be close to replicating the 2000N (204kg) braking force in sprinting experienced by one leg only at a time.