Thanks for the conversation functionalities in 3.28, BUT it is a bit complex in a NEW conversation.

You currently need to type anything in the message-field and then type BACK to save it as a draft, and then reopen the conversation. This works, but is not exactly intuitive...

Between the Person+ and the Exit-X there could be the usual vertical ellipsis, that could have an option to fix the recipients, and thus making it into an established conversation, and thus allow for changes like bulk/chat.

OR you could replace the Exit-X with the ellipsis and then have Discard and Fix as two items on the menu.