There could be a risk for you apps to be rejected by Apple, by sending MAC address without users' permission. Even though your code is not doing that, the 3rd party libraries you integrated may do. However, there is no straightforward way to detect it.
Use conditional breakpoint in Xcode (LLDB).
- Add Symbolic Breakpoint
- Set sysctl as a symbol
- Specify a condition like below (for device only. not for simulator)