As mentioned above.
Did they adopted Senju as their surname? (Purely example: From Uchiha Sasuke to Senju Sasuke?)
Did they fought for the Senju clan? (Probably against their old clan too?)
Did these Uchiha married Senju husbands or wives?
I feel the Uchiha clan's reputation was long gone once an Uchiha defected to the Senju.
Did the Uchiha who defected to Senju had a greater sense of peace?