Is it Polite to Just Finish the Race?

https://preview.redd.it/wtfckc2vukje1.png?width=2400&format=png&auto=webp&s=12ce1d3e0f9bf030051b6f8348971355e75e2965

Is it bad manners to just finish the event so quickly after it started even though the other players haven't gotten a chance to get their interim treasure chests?