I don't know if the sibl is still a constraint but it was basically the only option I added to a base XL EB and it arrived with the spray in from the factory.
I ordered my XL Hybrid 11th October, nothing was happening like for many of us so I spoke to my dealer. He said what about changing the order to an EB. I obviously wanted to know if I would go to the back of line, he said no. Changed it and then things cleared. Built I think late Feb, early...