That's a lot of space. Equipped with a really nice set of power supplies is well suited for connecting a bunch of pedals and also a multieffect. I connect my Helix Stomp directly from the pedalboard (with an adapter, as the power socket is different on the Stomp).
Keep in mind that it is already 3kg, and throwing lots of effects here will make it heavy as hell. So go to the gym or hire a pedalboard boy before setting up 20 devices.
I don't experience any significant noise, although my signal cables do not cross significantly with power cables. Plan the connections, and the interference should be negligible. It may not be the best power supply in the world, but for that price and capabilities, it is really a bargain.