There are no plans to officially use or encourage the use of BTRFS so no plans to add the management tools to our repo. Have you tried installing @lrusak's repo and installing it from there?
Yes. I tried to install the repo, but the tools don't work. I filed a bug report on github:
'btrfs: line 2: syntax error: unexpected word (expecting ")")' on LibreELEC 7.90.004 · Issue #11 · lrusak/lrusak-openelec-addons · GitHub
I'm a bit surprised to hear that Btrfs is not on your list at all. So I guess, I'm better off switching to another distribution.