> Flipper Zero (without extra hardware) doesn't do 2.4 GHz for Bluetooth or Wi-Fi (or 5GHz Wi-Fi).

Flipper Zero has Bluetooth built in, that's how the phone app works.

I don't know how much control the apps have over it, but there were definitely Flipper apps to abuse the BLE auto-pairing feature of a lot of devices and spam popups to nearby phones.