If golf instruction and the public could understand one concept, everyone would get better.
When you have a problem, the answer is not the opposite extreme.
When you cast, you don’t hold the lag, when your hips and body over rotate, you don’t restrict the hip turn.
A limited hip turn is very simple. You let them rotate freely, allowing the turn of the upper body to rotate the hips from the initial takeaway. When the hips reach their maximum range of motion, they will stop turning and the shoulders will continue. For those with proper, but not extreme flexibility, that will be approximately 45* and 90*.
A restricted hip turn is forcibly not allowing the hips to turn from the initial takeaway, the torso won’t rotate properly and the arms will create much of the backswing and will over run the turn or create a short turn/backswing.
When you look at it from that perspective, restricting the hips seems pretty stupid, but as I have said many times, “The opposite of bad,” teaching approach is common with many flaws.
Hips over rotate for a couple of reasons. The level of the hip turn is too flat, the upper body tilting toward the target, etc.
So your hip turn will limit itself and create your own personal maximum X-factor if you turn properly. What a concept.