Run ./format_test.sh in your own shell(s) to see how well it works. Report any inconsistencies, please.
If you want to include output-formatter functions in your own shell scripts, you can copy and paste from example-bootstrap.sh to get a consistent formatter target to hit that shouldn't break with changes to the repository. If any breaking changes are introduced, they will be tagged appropriately.
Documentation on the use of formatter's functions, variables, and file descriptors is, and will always be, present in comments inside of the release of formatter you're using.
Requests for new functionality, issues, and PRs are all welcome.