I would love to take a look to the SoulBound Engine's code. If it works as it's intended that will be pretty much the revolution every sandbox MMO that comes after CoE will be implementing.
The Heirloom as such doesn't interest me that much. Yeah it will add to the immersion, but you wont feel it's actual weight unless you get a heirloom from your mother and wife (sounds so bad X'D), meaning when you get into the body of your kid, or when you go into a new family and receive it. "Why?" you'd ask, because then it's not an item that comes from an ancestor. It comes from you. It's just an item you're taking with you from the beginning.