What controller calibration changes
Manufacturer apps, Steam, and some replacement modules rewrite how the pad reports rest and outer reach. CTRLCHK cannot perform that write through the Gamepad API. Use those tools first, then measure here.
What CTRLCHK can measure
Centre is the same five-second hands-off capture as the stick drift test. Range is 8-sector outer coverage. Circularity is rest-corrected envelope error from those range samples. None of this is a firmware programmer.
Before vs after calibration testing
Run the workflow, note centre and range, calibrate in the vendor or Steam tool, then measure again on this page. If this tab is still open, the second run can show a before/after delta for P95 and range. For rest versus outer path, compare with the circularity test and the deadzone test.