While I wasn't able to figure out *exactly* why the old format didn't work, re-factoring the `parseOptions` function to use `yargs` differently "just worked" so that's hopefully good enough here.
With these changes everything related to a *particular* option now appears in one place, rather than being spread out, which aids readability in my opinion. Also, the options are now sorted alphabetically, to make it easier to find a particular one.
https://www.npmjs.com/package/yargs