1) No metaphor in philosophy passes the algebra test without tweaking it. This one certainly does not. The parallel construction is poetic, not mathematical.

2) While "binary" can explain almost anything,
it cannot explain undefined terms. Brain-based
though we may be, it is also fair to say we are information-based, nutrition-based, legally-based etc. All these have a tremendous effect on the brain's performance, and are in return programmed in part by brain-ular :) performance.
And for the "capper" ...we employ prosthetic devices to extend our brain's abilities, such as
paper and pencil, prefab models like geometrical
theorems, or computing equipment.
Mike