Originally posted by biz-engineer By release priority, I guess you meant focus priority. It's a solution for catching fast moving subjects when the zone of focus is predictable.
My original intent was to link CIF with the AF button on the rear of the camera. This way, shutter button alone releases the shutter regardless of focus lock, but the shutter + AF combo engages CIF. For this to work, the AF switch by the lens mount needs to be on all the time. If that's true, then release priority is required in order to allow shutter to go off without a focus lock.