It’s a great idea when I start a dialogue in Figma with other designers to give them the opportunity to invite them into the conversation.
Some kind of sound signal or popup so that they can hear that I am calling them to talk 
. like a phone call. accept or reject.
Only for participants who are currently working in the same file.
But in the future it is possible to call me to a specific file and talk there. And I will immediately get into the conversation on the file that I am invited to.
Because every time I go to a private chat on Telegram or Skype and ask them to talk to me in Figma.