4th Axis brake and LOCKING_INDEXER function

Has anyone been successful in using GPIO to control an A axis brake? It looks like I could set an open/unmapped GPIO pin into output mode and thenconnect the digital output to the hardware pin.
Anyone’s experience with this and any HAL changes would be greatly appreciated.

As mentioned on cnc zone the usb io card could be setup to do this with no special path pilot configuration settings

USB M-code module for anyone that is interested