Yes, I have one of these tools and used it, but it just flexed. I imagine the link was not exactly aligned, so put that down to user error. Also tried brakes on, stamp down at 3 o'clock. Whatever, I got the job done, but it was an inelegant performance.
I’ve found that applying the brakes and slowly standing on one of the pedals at the 3 o’clock position gets the job done easily.