Introduced in WebApp version 1.3.0, the ZonePad 1 input routing allows for the local input from any ZonePad 1 to be routed to any or all Zones. This is achieved by patching a ZonePad 1 input to one of the two system mics on a Zone.
To patch the local mic to the system mic functionality is simple:
Navigate to Settings > Audio > Microphones. Select the System microphones you wish to change the source of and you're set.