The improvement may come from freeing up the time and energy to spend on other aspects of Japanese. In terms of memorization in the short term, WK will probably be better since you are literally being tested repeatedly multiple times for each kanji. In my opinion, doing it this way will help develop a more visceral bond with the kanji. Plus, being able to physically write Japanese is a lot more impressive than just being able to read it
Your writing looks pretty good, it’s balanced and it’s consistent. It may look a bit robotic but that may have more to do with the font that you are copying from. I am going to second Asher’s recommendation of paying attention to stroke order, not just for the muscle memory but it will also help with making your writing more beautiful.
A pen recommendation that is fun to write with, not necessarily just for kanji
Pentel Brush Sign Pen Pack of 10