I booked the Yufuin no Mori 1 tourist train as soon as it became available. I am a tourist, after all. Many seats available on that train on that Tuesday compared to the weekend. Yufuin no Mori 3 was unavailable.

Later start to the day and easy connections. If I get to the station early then I might try making the non-tourist Yufuin 1 and bozrd an unreserved car/seat and then cancel the reserved seat on the tourist train.