Here is an unintended-positive-consequence that helped with the 'SMBC too Buttery' problem.
I had tripled my SMBC recipe, that already had cut the amount of butter in half ( 3 sticks of butter rather than 6).
To make a triple batch I used my new 7 qt. KA with the 11-wire whip that came with it. Normally I use the 5 qt. mixer with the 6-wire whip and it takes 10 to 15 minutes to get the SMBC to 'come together'.
After putting in only 6 of the 9 sticks of butter I was shocked to see the BC had come together and was creamy as could be. I added another stick for good measure. But it was shocking to have the mixer make a triple batch of SMBC in a third the time !! Very happy with this surprise result.