The Greystone Bastard (naming lore query)

[Emmanellain]

I would like to ask if we know anything about Ishgardian funereally laws. I want to see if there's anything requiring the use of the deceased name, bastard surname and all, on tombstones

Well what we do know is that his memorial by the lover's stone overlooking Ishgard isn't his actual grave, but a memorial commissioned by Francel. So it isn't his actual grave but a stone set in honor for him. My guess is that he's probably buried at a family burial site or near it. But that's all speculation on my part since we don't know where he's actually buried.