It would be good to have the possibility to configure as default the mandatory lobby for guests connecting via SIP and PSTN (while keeping no lobby for Webex app and Browser accesses).
The reason of this is that usually those type of connection have a lower level of trust eg. connection via SIP are not 1:1 but physical meeting rooms and for PSTN there is no nickname nor video to identify the participant.
In Webex meetings it's not possible to make a difference from guest with an account on the same tenant or not nor depending by the connection means.
Other competitors like Zoom or MS Teams have better ways to fine tuning the lobby access.