I tried the new calibration tool and anti-deadzone from ACSE, and can confirm that it's not working as intended.
When moving the left or right stick in the calibrated section of ACSE, i can clearly see the Red dot snapping to the Horizontal or Vertical Axis. Then with a 25% anti-deadzone, it's getting even worse, the red dot stays on the Horizontal or Vertical axis until you go full diagonal.
Please provide users with the raw output from the sticks, not some pseudo XBOX deadzone and sensitivity curve. Then build the tool so we can adjust it on the fly to our liking.
And for better user experienced on remapping button, setting up deadzone, you should display the movement of every press of a button, sticks and triggers on the configure view, like you are doing in the calibrated view.