There is something in the normal configuration landing distance tables in my QRH
Just wondering if I am missing something here, are you expecting this amber light to illuminate when arming spoilers or upon failed deployment? Either way there is not much time or no time to pick up a QRH unless you feel it appropriate to fly around a bit until you figure it out. In a deferral situation the obvious is to have prepared your penalty before T/O. I am of the mindset that the light's main function is to let you know you need to take all into consideration for landing and be prepared to manually deploy.