I can’t seem to bind ???
The 4-hole mod spacer is designed for off-string yoyos. It is also designed to go with the stock metal bearing spacers for the ProZ, or did it come with replacement metal spacers? I forget. You might want thinner spacers. You also want to use a good quality string, or at least one not all worn out, and throw some more string into the gap when doing the off-string bind.
I’m using these in both my Hayabusa and my Flying Panda. Big improvement on both yoyos.
Use a fresh string too if you can. It helps.