Hmmm, I'm obviously also not alone in being with your boss on this one.

I've never used Module::Starter - plain, good old h2xs has always fitted the bill perfectly well for me. With this make & make test are both dependencies of make install, so once the makefile has been generated, there's only ever one command to recall and re-run - and unless it's been Windoze-based perl/make session to a networked filesystem, any extra time spent is negligible ... to the point of being infinitesimally small.

The one thing I notice you haven't mentioned is the notion of unit test - the skeleton for which comes for free with h2xs (and possibly/probably Module::Starter) - and (as mentioned above) gets executed prior to installation - thus providing a far greater degree of confidence in the installed module (assuming adequate test script(s) coverage).

WRT ...adding another module would mean editing a MANIFEST file each time., you self-evidently haven't heard of make manifest (having first tidied up the development area).