Quarter-comma Meantone with split sharps

No, and yes. The difference is obvious even those who don't distinguish pitches much (can you hear the difference in the video linked in the article - ▶ this video ) because the 'wrong' one played in a scale or a chord sounds really, really horrible; that's why we have all the work done on 'tempered' tuning to reduce the gap so that everything is just slightly off.

Except for voice [0], any fretless stringed instrument [1], any fretted string instrument with separate frets for sharps and flats [2], keyboard instruments that allow expression [3], keyboard instruments with split flat/sharp keys [4], and electronic instruments that allow unorthodox tunings without huge hassle [5]... I'm sure I'm missing some, but other than that you're totally right ;) [0] link , link [1] link [2] link [3] link [4] ▶ this video [5] link

The list of export formats is really impressive. It's interesting to note that Hauptwerk (a pipe organ software emulator) is among the supported targets; some early organs used historical temperaments which sound different compared to equal temperament and some of those had split keys [1][2]. [1] This is an example of meantone organ with split sharps ▶ this video [2] This is an explanation of Meantone and split keys link