Just watched an older video from Angel Lemus, One of his One Minute Bunkai, in the case an application from his Kojo Ryu videos. A solid series.
But this brought training from Sherman Harrill in the 90s, in my own Isshinryu lineage. Perhaps it best illustrates everything new is old again, and nothing is new under heaven.
I recall the day Sherman had us slap our hands together. High and low, it made no difference we could do it. Then he had us close our eyes, and we still did it. Every time we could strike our hands.
Sherman explained that this was because it was a natural ability. Then it could be used to our advantage.
As an example he had someone strike to him with their left hand. Their arm came out and as it did so, he slapped their arm (behind the elbow) with his hands. Then he had them strike again. But this time he struck his right hand into his left palm their arm was between his hands. The strike went into their muscle, above the bone of their arm, and they dropped.
Harrill Sensei explained the supporting empty hand with the accompanying strike was the way the strike was focused. You can always strike your own hand, their limb just gets between the two hands.
Thus movements from Sunsu kata where there are two inward striking fists might be interpreted like this,
It proved to be a useful application. You might even interpret the inward hammerfist strike from Seiunchin kata, as a measured strike to the side of the head, or perhaps the neck, Just using the head as a limb to strike.
In a similar manner, the elbow strikes in Seiunchin kata, Wansu and Chinto kata, might use the same targeting.
The Angel Lemus video I watched.