I will be in Taipei on the 27th-29th, go to Yilan and Hualien on the 30th, and return to Taichung in Hualien on the afternoon of the 1st. Is there enough time for this itinerary?

If you want to have fun in Hualien and Yilan, it is recommended to spend at least two days each. According to your plan, you should allocate at most one day for each place, including traffic on the road.