Ummmm.............
SKK Combo 4, first the person is not going to fall down from a kick to the solar plexus. BUT, let's say you hit the liver with the kick or do knock the wind out of him and the attacker goes down. That's it! Self-Defense is over...get away! If you continue the rest of the attack, you will go to prison for a very long time for the damage you are causing to a helpless person (at this point).
Remember, the attack is against a punch, no weapon involved. You are good with the initial part of defending against the punch and offline to respond. The rest of it is just nonsense that will get you into big legal trouble. You jump and stomp on the attacker's face/head and then poke out both eyes and then kick his head/face again as you leave.
There isn't a scenario I can think of right off that the technique as shown is a tactically logical or legal response. Let's put in a knife into the mix for the sake of discussion so a lethal response would be legally justified in your response. You kick the attacker and then there is NO attempt to control the attacker's knife hand so the response doesn't make sense tactically. If you say that the attacker would "drop the knife" because of the kick, then you are not legally justified in the rest of the response because there is no threat of deadly force.
Let's assume it is a multiple attacker scenario that you are in fear of your life and chose a lethal response. The technique STILL does not make sense because you are taking WAY too much time on one attacker to disable them that you wouldn't be able to pull of that response because you would be pummeled by the rest.
If this was actually taught as a technique, the ONLY thing that keeps running through my mind is that it was a throwback to the "old days" when people did purposely hurt an attacker (think curb stomping) because he pissed you off and it has nothing to do with actual self-defense.
IMO, it looks like Combo 4 should have stopped after the kick and Prof. Cerio (or whoever added it) took a page out of Ed Parker's book on "extensions" and added in the rest of the moves on a downed attacker.