Would I be able to add to Messenger side bar extra categories? I would like to add something like Rooms and add a Messenger block on each page titled with a different category but under Under a Rooms section in slide out menu in Messenger
At present (in default configuration) you can not create new menu section via studio or messenger and connect it with special talks.
Each talk's block from any page is connected with the page's URL only. It means if each room with category has own unique URL, then all these talks will be available in main Messenger menu in Pages menu section and each page's talk will have own name the same as page's title. All Talks will have own dropdown area in Pages section and users will be able to create sub talks under them.