I actually know someone competing in Tokyo. Went to school with adult DS. Last spoke to her 3 yrs ago on the train. (And she's great in spite of results so far).
Anyway, she got knocked out in qualifying heats so won't proceed to potential medal contender or compete again in Tokyo 2020. What happens to these eliminated competitors? Do they get to stick around to cheer on rest of Team GB? Or do they have to leave right away? Does anyone know?