RBK40 as satellite?

I recently purchased a RBK40 with RBS40.  I only needed the RBS40 to add to my RBR50 system.  I purchased the kit becasue it was about the same price of just adding the RBS40.  The RBS40 setup to my RBR50 nicely and all works well in my 7K plus square foot home.  My question is can I use the excess RBK40 router as a satellite instead of in AP mode?  This way I can cover the one last small dead spot in my house without having a separate broadcast ID.  Thank you in advance for you input.