If the Wago device supports you doing that - it will work. When you write a value to that tag in the MQTT Engine provider, MQTT Engine creates MQTT DMCD message and sends it to the Wago device. It is up to the Wago device to write to the output, update the value, and send a DDATA message back to MQTT Engine at which point the MQTT Engine tag will update.
If the Wago device doesn’t support this, it will not update. At this point MQTT Engine is configured to send that message to the Wago device.