Giant circuit boards

[Gumby212]

What are the cons of building multiple overdrive and distortion circuits onto one giant circuit board, about 6" by 2.5", for installing into one large enclosure. Trying to put 6 or 8 dirt circuits into one single pedal, all switchable. I know i can do it, but not sure if ill run into any noise issues if doing so. Is this a dumb idea? Any tips would be appreciated. Thanks!