Actually, the "septimal diatonic semitone" of 15/14 is really a chromatic semitone (tempered out in 7tet), while the "septimal chromatic semitones" of 28/27 and 21/20 are actually diatonic (tempered to one step of 7tet). They are all actual semitones (tempered to one step of 12tet), though.

This took roughly 15-20 minutes of building and a half hour to run to completion.

This was previously called "7# or San Antone", after its R/P, but I spotted the pun on pitch and went for it.