It will depend on which fuzz circuit you are using. If the fuzz circuit INVERTS the phase of the signal, you will need to add a Stage 3 or other INVERTING circuit to the Buff ‘N Blend. This is discussed in the documentation for the Buff ‘N Blend.
For example. the P.U.F.F does not invert the signal while the FZZZ-BXXX does.