It should also work from forwarders. After launching the forwarder, hold the Y button to open the per-game settings menu. You'll see the same settings found in TWLMenu++.
Is there any possibility of a patch for the USA version of Shantae: Risky's Revenge to allow it to be played in English on a Japanese DSi from the system launcher? It works fine with region overridden when launched from TWiLightMenu++ on the same...