It strikes me that touch typing prose is actually very different to coding due to all the symbols. Also unlike prose, a lot of time is spent editing or refactoring the code. How much would you say your typing competitions actually have an impact on your coding speed?
Don't forget there's a lot of prose in software development, too.
You can always tell which people are comfortable writing their ideas down, versus those that don't, by how they express themselves in emails, issues, documentation, or comments in the code.
Note that good IDEs help with punctuation, and you can touch-type those, too.
