Is there any halachic benefit or hiddur to using an edible fuel for menorah? ( I think those premade menorahs use a olive oil that most people would find disgusting and inedible.)
see ס' תרעג הערה 29 -ספר פסקי תשובות who brings from numerous poskim that any olive oil is mutar lchatchila even if it is not edible.
This implies that edibility is not intrinsically of "halachic benefit" for the oil. This has no bearing on whether individuals chose to adopt a "personal hiddur," such as the stories of Rav Eliyashiv insisting on edible olive oil.