Comments by Danylo Maschenko

Reusing the names of 8:3:n leapers for a Higgler hex coordinate could unite Cormorant and the 7 level moving Entrap rotation with cubic pieces with twice their SOLL (Octodont, Onlooker), allowing Octodont+Cormorant (Coypu?)/Goose/Gull/Bustard, Jaw+Chough (Jamaican?)/Gosling/Guillemot/Budgie and Onlooker+Entrap/Nosrap (Nosferatu) on hex-prism boards.

the 2:1:1:1 is a Foal rather than a Sennight.

You're right! Quite right!

For every two-odds three-distincts cubic leaper there is a 4d one-odds/three-odds one with half its SOLL. By (dual(m:n:o)=((m+n)/2:(m-n)/2:o/2:o/2), where m and n are odd and o is even, the 4d Foal happens to be the cubic Fortnight's dual.

Likewise the pieces corresponding to the cubic 4:3:1 Arbez, 5:2:1 Monk, 5:3:2 Sustainer, 5:4:1 Votary, 5:4:3 Epoletna, 6:3:1 Genome, 6:5:1 Endower and 6:5:3 Dormouse are the 2:2:2:1 Aurochs, 3:2:1:1 Mountie, 4:1:1:1 Student, 3:2:2:2 Offscore, 4:2:2:1 Pentagram, 3:3:2:1 Germinator, 3:3:3:2 Newlywed and 4:3:3:1 Fanatic.

I just realized... the name for the FO Prizemouse kind of conflicts with the extrapolated name for Pamel+Tripper

would the plural of Dabbaba be Dabbabae? kind of like nebulae and spatulae

After a bit of 4d experimentation, it seems that while remaining 2d, hexagonal leapers use a 4-coordinate system rather than a 2- one: one m coordinate, and 3 repeated n coordinates. The latter's repetition could be explained by the Viceroy's SOLL of 3; for every O piece n=0, and for every ND piece m=0. You may have also noticed that some unbound pieces (2:1:1:1 Sennight, 2:2:2:1 Aurochs, 4:1:1:1 Student) have a Viceroy-bound one with thrice their SOLL (2:2:2:3 Overscore, 6:1:1:1 Barnowl, 4:4:4:3 Bettong). This is no coincidence, as if they are both a:b:b:b and c:d:d:d leapers respectively, then c:c:c = b3 and d = a:a:a; in fact you could compare this to the "relative multiplication" system on square boards, where moving an a:b leap c times in one direction and d in the other, as if you were moving a rotated+upscaled Wazir to a specific leap, the final distance passed will be (a²:b²)*(c²:d²). The earliest instance of oblique SOLL-sharing can be seen with the 8:3:3:3 Zemindar and the unnamed 5:5:5:4, both Sennight*Aurochs pieces.

There are in fact two more SOLL 129 pieces, one with 2 distinct coordinates and the other with 3, but they are both outside the 8 coordinate. For Filcher+Pilferer a good name could be FIREBRAT, a relative of the silverfish.