Im not sure this is possible, and i hope your still updating and working on your mods Saftsuze, probabbly not knowing you'll never see this but i'll leave it here incase you decide to come back to it one day.

Well, you know how you can place corpses in prisoner cells/Poles? What if you were to attach a Pole or Cell below the burial site, under the ground? That could act as a sort of "buried" status for your character, im not sure how you would have it accessible to the player and out of the way so its not sticking up through the ground but i got faith in ya.

I apologise if this is a too far out there idea, just thought it would help have a good day / afternoon.