No.
Ecu isn't designed for it.
To be clear, the dbw ecus control the cruise control, there is no cruise ecu. Earlier cabled cars have a second ecu which talks to the engine/gearbox ones, but again the engine ecu isn't designed for an adaptive element...
The only thing they might do is allow for a throttle increase subject to load criteria, ie steep or long inclines although in my experience, the 3.2 was rubbish at maintaining speed uphill...
Mine works really well uphill, and downhill isn't too bad. When reaching an incline the gearbox kicks down to maintain speed. Downhill does have a speed increase, but it does drop a gear to assist with engine braking if the torque convertor deems it necessary.
There is a tolerance of maybe 2mph either side of the chosen setting on a flat road.
It would be the icing on the cruise-cake to find a simple way of adding adaptive.
Perhaps somewhere, somehow, there is a Vauxhall that has the same throttle cable control unit but also has the radar sensors mounted in the front bumper linked to the cruise control.
That would have my attention. I would study it.
I want to have my cruise-cake and eat it.