I built hyphen_greater.liga and less_hyphen.liga which are resulting in rightArrow and leftArrow, and I’m wondering into which category I should put them:
Glyphs automaticaly adds less_hyphen.liga to the symbol category, while hyphen_greater.liga ends up in the punctuation category.
Is it ok to leave it like this, or recommended to put both glyphs into the symbol category as arrows are symbols?
They are ligatures, and the first glyph in the ligature determines the category.
What you could do instead is add a dlig feature that simply has rules like sub less hyphen by leftArrow; etc. I do not recommend liga because it could cause too many unintentional triggers.