Has anyone added a DCS Commander to their DCS WIU/TIU?
Although I haven't done this, you should be able to have both the app/TIU/WIU and the DCS Commander active at the same time, even on the same tracks, as long as you only use the DCS Commander as the power for the tracks and run the TIU in passive mode.
However, you'll be limited to using only 6 amps of DC power, since that's how the DCS Commander works. In my opinion, it's just not worth the effort. You'd be better off using a remote alongside the app.