It never records, and never sees what you say
JoyHarness doesn't touch the microphone, doesn't do speech recognition and uploads nothing. The only time it goes online is to check for updates. It turns controller buttons into shortcuts, so whatever you say through Typeless or any other tool never reaches it.
Settings and status stay on your Mac
What each button does, whether a controller is connected, whether responding is paused: all of it is stored on your Mac, to show the current status, restart the service and remember your changes.
Why it needs Accessibility
That's the macOS switch that lets an app press keys for you. JoyHarness reads the Joy-Con directly, doesn't ask for Input Monitoring and doesn't watch your keyboard.
Diagnostics are exported only when you click
When you click Export next to Diagnostics in About, the file may contain the version, connection status, permission status, service status and error messages. No recordings, and nothing you said. Whether to send the file to anyone is up to you.
Your voice tool has its own rules
How Typeless or any other voice input handles your voice and text is outside JoyHarness's reach. See that tool's own privacy policy and settings.