Some basemalts do add some color and flavor whether or not they are mashed, but addin some base grains evidently helps in steeping as well.... I asked Forrest of AHS about it in his kits, on another thread...here is what he said.
Originally Posted by Austinhomebrew
We added 2-row to all of our kits. 2-row has enzymes that (in theory) help "convert" more sugars and flavor out of the specialty grains. It is a good idea to add a little to every recipe. If you read about 2-row and mashing. it has nothing to do with getting the sugars out of the 1/2 pound of 2 row added. We add it for the enzymes and not the sugar. If you were trying to convert the sugars of the 2-row then you would need to steep it longer. If you follow the instructions you will be ok.