Hey,
Patching anything in the Pitch input will break the connection from the keyboard to both VCOs.
For attenuating pitch modulation, using the FM input is more suitable as it is added to the keyboard CV (+ you only need to plug one cable)
The "Pitch" input was more designed to be a master pitch cv in that you'd use to control the MiniBrute 2 from an external keyboard.
Hope this helps,