Agree!I think there's still personal expression in the performance of KKW forms, even though the techniques are very standardized.
beginner level (learning stage) - you copy every moves down from your teacher.
intermediate level (polishing stage) - you make every moves to be perfect.
advance level (art stage) - you add your "personal flavor" and make it into "art".
I think the OP is only interested in "how to improve in Kata" and not "What's the best way to train Kata"?But that may be more subtle than the kind of help Azulx is looking for.