Safari to the Rescue
I proceeded to spend several hours attempting to diagnose the issue by using a combination of desktop Chrome (and its
alert()s) sprinkled throughout my codebase.
Finally, I got sick of the
alert() strategy and googled for a way to see
console.log() output from the iOS
Simulator. What I found exceeded my expectations and greatly sped up the diagnostic process:
With the iOS Simulator launched and running your local site in Safari, open your _desktop_ Safari app and click on Develop -> iPhone Simulator -> localhost. You'll get the full suite of Safari's development tools at your disposal for your iOS Simulator's browser!