Sprinter Audio 5 replacement with aftermarket head will call buttons work?

Hey all I am getting mixd information on multiple forums and vendors.

I am ordering a sprinter with audio 5 to get access to the canbus as with just the audio prep you don't get access to the can bus with out it I have learned.

I was told by a tech at metra what if I use there steering wheel converter what if factory Bluetooth was not activated it will not work when I do a replacement.

I have seen people on forums say that they have got it working but no one can say what devices they used because they had a shop do it I am planning on doing fit on my own as the vendor in my town quoted me 8,000 to install an after market system with rear video etc.

Thanks all
will