XEP 0045 disco#info response is incomplete
We should respond with more things, like for example http://jabber.org/protocol/muc#roomconfig
See https://xmpp.org/extensions/xep-0045.html#disco-roominfo and https://xmpp.org/extensions/xep-0045.html#registrar
To upload designs, you'll need to enable LFS and have an admin enable hashed storage. More information