[4] In August 2018, Plapp won the points race as well as the Madison with Blake Quick at the UCI Junior Track World Championships in Aigle, Switzerland.

[5] Plapp also placed 2nd to Remco Evenepoel in the time trial at the 2018 UCI Junior Road World Championships in Innsbruck, Austria.

[6] Plapp is part of the AusCycling High Performance Podium Academy and was selected to compete in the Team pursuit at the 2020 Summer Olympics, where they won the bronze medal.

[8] On 16 January 2022, he won the Australian National Road Race Championships after chasing down and passing James Whelan with under 10 kilometres (6.2 mi) left, before finishing solo.

Plapp himself managed his first World Tour top 5 on the 7th and final stage to Jebal Hafeet in which he finished in 5th place, 16 seconds behind winner Tadej Pogačar.