The techniques of karate kata have many possible interpretations. What each individual sees in the kata will vary according to their own experience and how skilled they are at identifying potential applications.
Not every application taught need be practical.
As a case in point in my Shotokan classes I teach a wrist grab defence using kata movements that isn’t the simplest or most effective method of escape, but is a very effective drill for teaching appropriate positioning, optimum biomechanics and principles of controlling and unbalancing. While doing so I always stress that it is drill about biomechanics and usually show the faster escape. In similar vein for my Heian / Pinan Sandan drills in both the older Heian Flow System and the more recent Pinan Flow System I included a spinning back elbow and back fist. While this has been successfully used in the UFC, it is not the most practical of techniques, but its inclusion was to a large extent to illustrate that point by making it an opening for students to unpredictably encounter a number of different positions and attacks which would lead to spontaneously training other drills.
When an application is specifically designed for practical use I notice that some people often fail to see the wood for the trees.
It is easy to over-focus on mimicking the techniques or sequences of the form but forget the overall context. If you need to strike, control or escape from another person then they will also have an agenda.
This means that they are unlikely to be holding you limply, are likely to be prepared to hit you, or may continuously be trying to hit you or get to a position where they can hit you unless you take steps to prevent that. Always protect your head and as much of your body as you can.
Unanticipated aggressive and violent confrontations tend to cause a significant adrenaline release unless you are very familiar with them and a non consensual or unpredictable event will cause different reactions to a predictable or fully consensual one. In such situations even very well trained people have difficulty utilizing fine motor skills or targeting accurately and this should be reflected in applications (for example see my kicking in self defence video). The same hormonal cascade (along with other substances) may render pain compliant / dependent techniques ineffective.
The context of the drill should be realistic if the drill is supposed to be for self defence. Appropriate habitual acts of violence (HAOV) rather than style or rule format specific attacks, and not over-skilling or under-skilling attackers / training partners. In similar vein you need to be clear whether what you are doing is legal for the envisioned circumstances if you are training it for practical purposes rather than historical curiosity.
Hitting or striking a resisting person isn’t as easy as working with a compliant training partner. As a general rule at close quarters (where most violent incidents occur and remain) you will need to strike to control and control to strike.
When people get hit, they move, even when you are holding them. Combinations should take this into account. This quickly becomes apparent when you are making contact or receiving contact in training.
The potential of practical karate kata application is incredibly vast, but when interpreting kata for such purposes the ‘trees’ of the individual skill sets should always be seen within the context of the wood that represents the nature of actual violent confrontations.