Split them
Kota Kinabalu: waterfront and islands one day, Kinabalu another. Kuching: waterfront one day, Bako another full day. Between them is a flight, not a walking next stop.
Guide · East Malaysia
Do not join Sabah and Sarawak as a walk or as one day.
East Malaysia means flights
Kota Kinabalu: waterfront and islands one day, Kinabalu another. Kuching: waterfront one day, Bako another full day. Between them is a flight, not a walking next stop.