Bluetooth Steering Wheel Control

[sfplayr04]

I've decided to get the Alpine INE-W940HD HU for my car. The shop that will be doing the install claims that they can retain the use of my factory backup camera and all of my steering wheel controls. Through all of my research, it seems as though the steering wheel button for bluetooth will be rendered useless once this HU is installed. While the shop did not guaruntee me anything, the installer seems to think that I will still be able to use the Answer/Hang up function of the button. Does anyone know if this is true? Or will I lose the functionality of that button all together?

[AlexN09]

With my head unit I can assign my buttons to do whatever I want them to. I am guessing the installer probably knows what he's talking about.