Yes, IO::All was the brainchild of mad scientist Ingy aka Brian Ingerson aka Ingy Dot Net (who is also the original co-author of YAML).

Since you are developing your own modules, you might be interested in On Interfaces and APIs, especially the "Conway's Sufficiently Advanced Technologies" section, which describes an approach to module design by another mad scientist, Damian Conway. Conway's SAT-approach can be seen in an older module by yet another mad scientist, Mark Jason Dominus aka MJD, the original author of Tie::File (found some old MJD slides on Tie::File here). While Tie::File made it into the Perl core, IO::All did not.