One of the proposed linked options is the Mushroom Death Suit from TED 2016. Sounds good to me:
https://www.youtube.com/watch?v=PRsopS7yTG8
Every year > 130M humans are born and >55M humans die. As mentioned in above article / video cremation isn't a very good option either as it ejects over 5,000 lbs of mercury into the atmosphere yearly.
Seattle trying to help make human composting happen:
https://www.wired.com/2016/10/inside-machine-will-turn-corps...
That's pretty much irrelevant. Half of the mercury in the atmosphere is released naturally. The other half is mostly coal plants. Then there's some industrial processes.
https://en.wikipedia.org/wiki/Mercury_(element)#Releases_in_...
Edit: to be honest, just for myself, I don't think I would want it for any loved one.