Ooh - adding credit card(s) linking - well, Barclaycard(s) linking - is now available with Joint Accounts. Nice.
Edit: Doesn’t seem to work. Or doesn’t display immediately. Sign up via Truelayer goes OK but Monzo doesn’t display credit card details in JA. Will remove card from PA & retry linking in JA in case there is a conflict.
Edit#2: Removed c/card linking in labs and started from scratch in Joint Account - switched on c/card linking in labs, went through the linking process via truelayer & was successfully returned to Monzo who informed it was all successful. But no card details shown at the bottom of the (Joint) Account tab. Only “+ Connect your Barclaycard account”