Gull have expanded the locations where B20 is available. I have noticed it at a number of places which have only one diesel bowser, meaning that it is there to the exclusion of 100% diesel.
They would have only done this if the majority of motorists at the initial trial outlets purchased B20 in preference to 100% diesel.

the customer has spoken.

The attendant has told me that Gull are considering increasing the blend ratio, but this will depend on their supply of B100 for blending.