karapalm is the common term for yun’s palm strike with added range.
it is not about doing palm strikes quickly, but rather, about canceling the animation of a standing strong with a short kick, and also canceling the short kick with a palm strike. so it’s about doing all of those 3 very quickly.
for this reference, it is done in genei-jin.
it will look like yun’s standing strong [the far elbow]. then he will stand where the elbow ends, the move forward a slight second, and then his palm strike.
to do it, while in genei-jin and in corner, do stand strong, then very quickly do quarter circle back, short, and an immediate jab.
you can do this in any variation during a genei-jin. there’s no set way to do it, but for full effectiveness, most of the hits while in genei-jin should be the kara-palm. it’s advantage? pain.
technically speaking though, kara-palms do not have to be in genei-jin. a true kara-palm ISNT in genei-jin. it’s just a short canceled to palm. quarter circle back with short -> jab. the importance in genei-jin is that a canceled strong is needed to achieve better range in order to juggle most characters with all palms.
a hint on how to master it is to know the timing of when to cancel the strong animation. too early and you won’t get far enough. too late and yun’s already back to his initial position. the pause between short to jab is of minor, but also importance. you’re given a few frames to delay the jab, since the later you delay, the farther the palm will be. but this distance is minute.
the practical usefulness of it is a different story. barring any players who’ve completely mastered the kara-palm and can do it flawlessly, the advantages do not outweigh the effort put into the practice. during tournament play, you do not want to risk doing kara-palms, because if you miss, you risk losing the entire genei-jin. therefore, it’s more of a risky crowd-pleaser. in casual, do it all you want. it’ll make you look 
