As per our Fuse 7.1 Release Notes:

Karaf console commands for child container administration have been removed in 7.0

Since Fuse 7.0, the Karaf console commands for child container administration are not supported. That is, the console commands prefixed by instance: (Karaf 4.x syntax) and the console commands prefixed by admin: (Karaf 2.x syntax) are not supported.

Note: In the Fuse 7.0 GA release, the instance: commands are not blacklisted. This is a known issue.

If these are really unsupported, I suggest to remove (i.e. black-list) any Karaf commands that allow to create or control child containers.