Augmenting Heroes Not Deployed or Supporting

[Spinozaro]

I've noticed augmenting heroes not deployed or supporting still raises your BR. Can someone explain why this happens or what stats are raised that cause the increase in BR?

[Londyn]

Hello, may I please have your in game name and server? Can you please tell me which hero that increases your BR when you were augmenting it that does not belong in your formation/support

[Spinozaro]

Server: [S1] Paramount
Player: Spindora
Augmented Hero: Edith & Thane

Edith and Thane are the only two I have tried so it seemed to me it would happen for all heroes..

[E.Soltrin]

I augment all my toons information or not... i see the +BR pop up but i dont see my overall BR increase (or maybe i just didn't notice ).
I know augmenting the toons satisfies the requirements in the "Gallery Bonus" which ups BR.