Hi NJ-MKZ,
I can explain this for you. First of all,
1. The volume levels of the various audio sources are controlled primarily by the radios. Other channel characteristics factor into the equation, but the radios provide the primary mechanism for volume control.
2. Radios are not updated in the field unless it is a repair or replacement situation.
3. Your phone is also an important part of the chain and only you can set the volume on it.
The strategy of having the radio remember the level that you set will be improved going forward, so in newer vehicles you will be able to set the level while the particular activity is active and the system will remember it consistently.
We might come up with a workaround that can be implemented in the Sync software, but that might not work the best in all scenarios. This is under investigation, and any progress in this area will be announced here on SMR. I hope that helps.
Mike