Normal conditions it is RWD and then switches to AWD when it senses the road conditions are slippery?
It's more seamless than that. The awd software takes inputs from the wheel sensors and the stability control and applies (correction) clamping pressure by means of an electric motor and worm drive to chain driven wet multiplate clutch progressively to transfer torque to the front axle. Actimax. There's video elsewhere on this forum.
Unless Alfa chose some weird version of this the system sends up to 100% of available torque to the wheel that has traction. The torque split front to rear is not limited nor is the torque split left to right.