- The usage is user-friendly.
- Backwards compatible with AddMusic 4.05 and AddMusicM ports by adding special headers to old MML files.
- Porters can define their custom N-SPC instruments in an official way, plus 16-bit tuning value support like the standard version of N-SPC.
- The song can encounter noticeable slowdown easily if too many N-SPC effect used at once. This issue is fixed since 1.0.6.
- The game will experience a long period of lag while loading a non-global song.
- When pressing a P-Switch while one is already active, the P-Switch music will not restart from the beginning. A custom version of AddMusicK 1.0.5 was created by another individual to solve this problem.
AddMusicK 1.1 is an unofficial improved version of the original AddMusicK by Codec, with more new features and bug fixes. However, there is no information regarding whenever it will be officially released.