gK should be able to be written as [jS?Q] but the latter moves completely different
gQ4 i expected to be a grasshopper, not a lion, limited to 4 tiles in total, the case of up to 4 tiles after hurdle can be constructed using square brackets [gQ?Q3] (i think, doesn't work in the diagram on the page)
h on it's own has no definition, something like relative half, from the halfling, could work
This does make left-only half impossible as lh and hl already have a meaning, you could use a punctuation like a comma , to seperate them so that the compound doesn't work, with this , you can make a move that's initial and non-leaping, but does not create e.p. rights i,n
t could be used for checking if there's a piece there, adding c or d to specify enemy or ally piieces
Somethings i want to note and some ideas