I suggest adding a new chat mode that allows only users with "permission to talk" to send messages to a chat; call it a "VIP-Only Chat" session, for example /viponly.

This would allow creating limited chats that not every single subscriber is allowed to join in on, which could be very useful if there are too many participants in the chat to carry out a discussion with readable interaction between chatters.

But also allow moderators to also give one user or a few users permission to speak that would allow others to speak that does not have the limitations of the /vip command where only a small number of VIPs are allowed by the system, and only the broadcaster can add/remove.

Being able to grant permission to speak individually would allow channels to have large events including chat in the event but structure and organize the chat sessions more, if they like, in order to cut out 99% of the unrelated messages, random chatter etc, and make it more feasible to showcase interesting discussions.

Moderators should then have access to a command which can grant or remove permission to speak. For example, /voice username /unvoice username
/unvoice all

Possibly with an optional time limit and reason to be sent to the user:

For example /voice username 10m Ok, username, you have the floor.

I would suggest that /voice command also allow such user to speak in Subscriber-Only or Follower-only chat regardless of other user status.

Channels holding such an event might have the people who will talk in chat arranged ahead of time with a prior agreement to the rules, or it might be audience members who joined an external queue chosen in order or randomly, or people that made a request through an outside system or authorized chatbot to be reviewed by moderators before granting permission to chat, etc.