Updating a cape physics system to be used for flags

I am trying to make a flag using some cape physics by EgoMoose. Currently, I am trying to make it so the flag Y does not change when you stop moving. Instead, I only want the X and Z to change. If anyone can figure out how to do this, it would be much appreciated. I have linked the place file down below.

PLACE FILE
flag.rbxl (31.2 KB)

Thank you for taking the time to assist me.