Interestingly, the modding scene often combines patches. There is a well-known Spanish translation patch for the game that is fully compatible with the version (voces en Japones). If you install the "TraduSquare" patch over your Undub-decrypted CIA, you can play the game in Spanish menus with Japanese voices.

: Modern versions of the undub (v1.1) include fixes for specific cutscenes that previously had issues, such as those found in the Neutral Ending path. Performance & Emulation Details

The UNDUB patch sometimes increases bitrate demands. On Citra, increase the "Audio Stretch" value to 40% and enable "Real-time audio."