I don't believe Stun Threshold works correctly. Please test it

https://www.reddit.com/r/PathOfExile2/comments/1ijap26/800_stun_threshold_and_no_difference/

Whether or not this thread did its testing right, my experience with Stun Build-up maps is terrible. I don't feel like you can run this map mod on a life character that isn't using overpowered concepts. I grapped everything I could and still perma-stunned, including Unwavering Stance and everything close to it relating to threshold.