I find that I can knee kick at the same range I can leg kick. the Wing Chun lop gerk for example is quite close range.
In sparring I still press the knee, I just don't strike it. I don't know that it's so easy for me to change muscle memory so quickly.
For JKD however, I believe we should focus on the knee, along with other areas of structural integrity. Wouldn't this be the most simple way to stop someone?
You can , but what I think you are talking about there is more of a stamping type kick.
Where instead of the leg coming up from the ground and maintaining much the same angle as it was in the stance , there is a slight chamber so it can stamp down.
In that case , the hook kick can be in the same range , as long as we are talking about impacting with the shin about three inches above the ankle.
But personally I find stamp kicks to be better suited to targeting the back of the knee joint on a side on opponent , it breaks the angle of their leg and just collapses it.
When you focus on the knee from front on it is easier to halt their advance , because of the simple fact that your bone structure is in the way of them moving forward.
Your body mass is directly behind your shin bone , femur bone etc , so basically all you have to do is time your kick so it impacts with maximum leverage and it will provide a barrier as well as doing a lot of damage.
That would be ideal , but if you find yourself closer than this range then other options are to attack the back of the knee joint , or attack the nerves in his thighs with your shin.
But as a caveat you should not open with a leg kick because it can put you within his punching range , use it as a finisher after a few of your own punches.
People are usually quite surprised with the amount of power that can be generatated with these close range hook kicks.