Hi! 
I don’t know has another ways without make some front-end changes You can send a JSON with all message and use a front-end to read and write
or use python list
Multiple messages need some careful because rasa is asynchronously
dispatcher.utter_message(text=first)
dispatcher.utter_message(text=second)
dispatcher.utter_message(text=third)
Working because it’s small but if you want to increment (maybe, more than 5), rasa will be return timeout error
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