This is a discussion topic for the Ore project, Shulker Box Backpack. View the full project on Ore for downloads and more information.
Useless right now, waiting on https://github.com/SpongePowered/SpongeCommon/pull/1214
Feel free to comment.
Is it useful now changes were made ?
Unfortunately, I am trying right now. When I finish that pull request, I may release another version that is verified to work.
Just curious on the progress of this. =)
Still waiting…
No news ? 
maybe since 2017 now its possible ? x)
This one is dead. Sorry.
No problem I found an alternative with a forge mod ^^ Thanks!