Other cores are less useful, with known incompatibilities and other emulators available that are both faster and more accurate. The GBA emulation was derived from work done in bsnes for the ST018 coprocessor, but is slower and less accurate than mGBA. Its Atari 2600 emulation is well behind Stella and MAME, and its PlayStation emulation has some noticeable compatibility gaps that you won't find in DuckStation or Mednafen.