I asked this very question of the dealer - I asked if (a) I could drive it, and (b) if it was safe to drive. There was a pause at the other end, and I then reminded them I only bought the car 4 days ago. The response was "don't drive long distances". That's impossible for me, as I bought the car in order to drive it... They explained that I'm effectively driving it without DSC or DTC.
I'm trying not to get in a twist over it, provided I get the right service when it actually goes in. I could let it really rile me and take the sheen off my ownership!
There's nothing I can do about it as I want to keep the car (rather than going down Sale of Goods Act etc) and just want BMW to fix it, and fix it properly.