This follows on from the issue reported as https://rt.cpan.org/Ticket/Display.html?id=37287
I've been working on Regexp::Trie a bit on a Github fork here:
https://github.com/kaoru/Regexp-Trie
As you can see from the commit log I've added two methods regexp_string() and regexp_with_modifiers(), improved the tests, and updated the POD a bit here and there.
Feel free to take all or none of the changes :-)