Is there some advantage to Chinese/other language or why else would it be specified for each run?

It is the fastest language. It ends up being 36 seconds faster than english

https://docs.google.com/spreadsheets/d/1jZH6fI6DFOBH6J1mIhWtr1UKWnmoOIxQzHhD7p60_IE/edit#gid=0