Currently the OpenVPN interface we have built will only show connections per-user. Also note that the superadmin status is not automatically transferred from Cloudron to the apps as such.
Maybe this could be a feature request to the openvpn app for us. But it is currently simply not implemented.
"I even had him log in to my account and he can still only see the accounts he has created." that I am not sure about which accounts you are expecting to see to be honest.