The drop doesn't worry me as much as the progression you have been doing. Have you been training by conditioning, or taking progressively higher drops? Once you start to drop higher than your own body height, it becomes indefinitely bad for you. This drop sounds like a fun feat and accomplishment, but it isn't healthy no matter how well you do it. I suggest you do a HUGE warm-up, a few rolls before hand, and when you're done... call it complete with the big drops and work on faster, more shallow jumps.