Let's crowdsource the secret features in Webex Meetings that you need to request to be enabled by your CSM. Add the ones you know in the comments and I will update the doc.
Allows you to set default sessions for new users or change global settings like ability to record meetings.
SSO and Non SSO Login Authentication Timeout
Customised dial strings in the location field
Meeting Center Feedback Survey
Access Anywhere - https://help.webex.com/en-us/WBX51223/What-Is-Access-Anywhere
Active Speaker Video Position in Downloaded MP4 Recordings- https://help.webex.com/en-us/WBX000028406/Speaker-Video-isn-t-Contained-in-a-Downloaded-Recording
High-Definition video (720p) in the Cisco Webex Meetings Site Administration - https://help.webex.com/en-us/WBX51163/How-Do-I-Set-Video-Quality-in-Cisco-Webex-Meetings-Site-Administration
End to End Encryption in Meetings - https://help.webex.com/en-us/n4f016ab/Use-End-to-End-Encryption-with-Cisco-Webex-Meetings
Seems like it should be there by default, but I'm pretty sure my first org and now a newly deployed org both didn't have the "Add Site" button under site administration.
This (add site/delete site/redist licenses) were initially Cisco\partner only functions, which can now be optionally delegated to customer admin on a per-org basis. If you're not seeing it, hit up the partner that services your Webex subscription.