Mr. Werner built his pedalboard from scratch and equipped it with original contact
system based on magnetically-operated solid state Hall switches (data sheet here).
These Hall switches can be used with mpc32xrs directly and don't require any customization.
The only signifficant difference between them and Reed contacts is that Hall switches require power.
In exchange, they are more reliable and proof to vibrations and shocks
as there are ni moving parts inside them.