How do I hear custom ringtones for calls in my Bluetooth headset?

This may only be relevant to those on Android 3 and lower.

Thanks to Raul Viaux for this information.

He basically wanted to hear his custom ringtones for incoming calls through his headset. This is how he accomplished that:

  • Talking Caller ID: enabled
  • Repeat Notification: disabled
  • Delay Notification:  1 
    Extremely important because if this is set to 0 no voice or ringtone reach the BT Headset. A side effect is that you will hear one second of ringtone through both the Phone Speaker and headset; afterwards, voice and ringtone sound through Headset.
  • A2DP Aggressive: enabled 
    If this option is disabled no ringtone is heard through the BT Headset, only voice notifications.
  • Disable Ringer: disabled