When I teach, I tell ppl point blank I dont like using weights during training and dont fele the need for them in
MOST cases. I think the answer to your question is rather simple. You want to get better at kicking????? Then kick more and owrk on proper execution of technique. Not speed and power. Learn to do it correctly and speed and power will come.
I have a friend of mine whom Ive known for over 35 years, he was one my second instructor. who ever would have thought we would now be such close friends. But anyway, John began in TKD, I went to his class one day and he was helping his studnets stregthen their legs. Seems he was having 1000 kick night. Nobody but John made it that night but over time I got to the point where I could. now at 45, I cant kick 1000 times but if i connect once thats it.
I have to this day really good leg strength and what some ppl would say very powerful kicks, I say decent.
So how do you get better at kicking????? Simple KICK