Please note that when organising a webmeeting you cannot change the meeting options. You can only control the Audio video and chat features as well as the server and the bitrate.
You have the option to organise a webinar however
This will also allow you to configure the options "Organiser must connect first" and "Hide participants from each other"
The profiles cannot be changed at the current moment, you can however create a feature request in our Ideas section of the forum where it can be upvoted by other users and evaluated by the appropriate department.