Even though the SG is down, I wouldn't do anything until the krausen falls.
Even if there is no butterscotch taste, there still may be some diacetyl. It's only butterscotch in large amounts- in smaller amounts, I'd say that it is "slick" or oily. If you taste it again, see if you have any oiliness on your tongue. It's more subtle than the buttery taste, but it's a definite sign of diacetyl.
I had a maibock in the primary for 2 weeks, and I racked it today. No diacetyl at all, so I just racked it and will begin lowering the temperature tomorrow. I used German bock yeast, and pitched at 48 degrees. I fermented it at 47-48 degrees.