In the safe jump setup the j.B doesn't have to be a hyper hop, you can do a hop j.B as well. I typically do neutral hop j.B.
If you screw up the timing of dp+A x2 then yes, it won't be a 4 frame safe jump anymore. The reason being is that you need to knock the opponent as high in the air as possible, so that when you do the hyper hop j.A you have enough time to land and do the safe hop j.B.
For example, if you do dp+C, and then try to do a deep j.A but you mistimed it slightly. If you recognize this and try to salvage it with hyper hop j.A, hop j.B it won't be a 4f safe jump anymore. Meaty c.B's aren't safe to being with and are susceptible to certain reversals.
The safest things to do in those situations is to either do j.C (instead of j.A), Grand Rafale or bait out a reversal after the j.C/D/A. You can take some risks and do other mix ups but it really depends on how your opponent plays.