Don't check for the iOS 15+ and processor A12+, check for the iOS 15's 'Live Text'feature support. Create a helper method with the following check that will return whether the device support live text or not

Sample:

var isSupported = true
if #available(iOS 15.0, *) {
    let check = UITextField().canPerformAction(#selector(UIResponder.captureTextFromCamera(_:)), withSender: nil)
    isSupported = check
} else {
    isSupported = false
}

print(isSupported)

Using the above condition will return false in the case of the device having iOS 15+ but not having hardware support.