Hello again! If I understand you correctly, the Control Watcher Actor in combination with the Jump Actor will work well for you in this case. You can allocate individual keys / pads of your MIDI device to trigger different Scenes via the Jump Actor.
From the Communications tab of Isadora's Menu bar select Midi Setup and choose your Midi device from the drop down menu. Then from the Windows tab of Isadora's Menu bar select Show Monitor. This will display real-time Midi info including Port, Channel, Controller number and Controller value. You should then be able to then work out the Midi Control number of each key / pad on your device.
Hope this helps,