So based on a conversation that started in the Corona Developers Network Slack group, I created a module that adds a "magnifier" object to any Corona app. The object is just a round display object, but it will automatically magnify whatever is beneath it on the Corona stage object. I have only tested it briefly on an iPhone 6S and in the simulator, but so far it works really well.
Anyways, here is a video I captured of a sample project to demo the functionality:
And you can find the code on GitHub: https://github.com/schroederapps/corona-magnifier
Hope some of you find it useful!