It seems to me that it's a bit too hidden for such a needed feature. I'm not a Perl newbie and even have experience with Test::More and I found it difficult to locate in the docs.

Besides the most trivial cases, lots of tests usually run autonomously, and generate copious amounts of output which is best contained in a log file.

I guess another solution in such cases is Test::Harness, which IIRC allows redirection of output from test scripts it runs.