Raptor has a good point. It's good that people are so willing to help thogh. I notice that whenever someone asks a question about their routine, people jump on it right away. THis is good.
To reduce the number of questions, I would say just follow instincts. Some of us look at it too analytically. I think the idea of counting reps is unecessary. Grount contacts? Doesn't matter. Workout ountil your performance deproves (no it's not a real word but it should be i think).
I've done 1 set of bounding in a workout (well two total because I switched legs), and saw an improvement the next workout. Plyos are not only about physiological changes in tissue, but also neurological changes. So it doesn't take much.
Trying to achieve a 5th rep, or a 70th ground contact could be detrimental to performance. For example, if you are at rep 50, and notice that you are jumping slower, you're not going to see any additional benefit in your explosiveness from doing those reps unless they come from collagen restructiring and increasing thickness of tendons, i.e. physiological changes. They also will train your nervous system differently since they will be slower. Just imagine crossfit box jumps.
Striving for a 5th rep, will result in a very slow grinding rep, and it may make you stronger, but it may have no greater effect than a faster set of 4 reps without the extra 5th, nd may reinforce a slow motor pattern. Sometimes there is a threshold in a workout for the gains, it isn't all dose dependent. But if you just want strength, it probably will help. FOr hypertrophy, it will most probably help too.