Well, that's easy: you just keep Slack running, but disable its notifications. Then you check your Slack from time to time and respond to all the questions that

Well, that's easy: you just keep Slack running, but disable its notifications. Then you check your Slack from time to time and respond to all the questions that came since the previous time you checked it. Text messaging is called asynchronous communication for a reason: if someone wants to talk to you synchronously, they call you instead of writing a message.