Yes, you may port your Team number out of Sideline.
From the app:
- Sideline 'Settings'
- Scroll and tap 'Support' (iOS devices) or 'Get Help' (Android devices)
- Tap 'Port-Out Number'
- Tap the 'Port Out' button to continue with port.
Detailed instructions: Port Out Steps
If you have any further questions, please submit a request.