Jumping on Elegon HC makes you exit his LoS and drop your cast afaik, that's why I swapped it out for a couple of tries. Turned out to be a slight DPS gain, at the expense of a little more inconvenience when moving outside of transitions (where I'll have SWG up). Difference is minor though.
Most of the time I just keep the glyph baseline really. We have plenty of raid DPS to not even sniff Garajal his enrage timer, and the glyph is borderline mandatory for every other fight anyway
. Plus, I can be an idiot and move while casting to my heart's content. Running circles around our Mage in his Rune makes me forget the sadness of swapping to my Shaman as a main since Wrath.