Why would I?
I do more reps on some movements now but that is my overall approach. I don't go in and do something different just for the sake of it. That would make it very hard to track progress long term.
fast twitch muscle fibers are responsible for the most growth. I set out from the start to maximize the growth in that department with full knowledge that I would eventually work the ones slowest to growth if needed and progress stunted.
Can I ask you WHY you would do that for no reason just to throw it in unless at a more advanced level?
I base what I do on the progress made and how I feel during a training session.