No, they're separate baseband chips with Qualcomm-designed Snapdragon ICs running Apple-signed firmware with their own build flavors of Qualcomm's RTOS. Apple

No, they're separate baseband chips with Qualcomm-designed Snapdragon ICs running Apple-signed firmware with their own build flavors of Qualcomm's RTOS. Apple has to verify that the fab produces the low-level hardware exactly as designed, but nothing is going to sneak into that firmware.