You're asking a good question, how do you find depth in your training.
The best parallel I can give is if you find a really good book on Tai Chi Chaun that contains an instructors secrets from 50 years of study, it is likely it will take you 50 years to appreciate it.
There are many different approaches to teaching a system. Isshinryu's approach that seems to hurry through the kata, goes back to the way its founder originally taught the Marines, his system in a year or a year and a half (but he taught the Okinawans at a much slower pace).
But the pace you're learning something isn't the issue because you're learning their initial shape.
The real issue is time. I've been doing Isshinryu's Seisan Kata for 30 years. It takes about 10 years IMO for one to begin to relax, regardless of how you practice, hard as a rock or a more relaxed pace. Only when your muscles stop contesting against yourself does your center sink and your power increase.
You have an instructor, trust them and keep training.
There are layers of lessons if you seek them, but they're not found in a book, or a video. They come from always trying to have better technique, and enough training to begin to increase your power during execution naturally.
In the short order, yes intense, correct practice, under an instructor pushing you on small details can make a difference, but it still won't make the difference 10 years of training on any of the kata will.
And that means the kata you learn as a brown belt or black belt still will take 10 years to reach the point for those exercises.
There is much more, but until you can crawl, it's not important what else exists.
Bushi No Te Isshinryu www.funkydragon.com/bushi