The one place for your designs
To enable design management, you'll need to meet the requirements. If you need help, reach out to our support team for assistance.
Poezio should always send @jid in affiliation changes
https://xmpp.org/extensions/xep-0045.html#grantmember
0045 says that @jid should always be included in <item/>. Then if @nick is included, this nick is also registered for the user.
This function from multiuserchat.py seems like a good culprit.
Not sure if that needs a change in the /affiliation command's interface.