Come on now, let's be honest about this. It takes about 5 lines of code to use the Milkman Google Games ANE and another 5 lines to use the Apple Game Center. Your claim about needing "two completely different code bases" is totally facetious. They provide simple methods to check which platform you are on so you can call the corresponding methods; I wrote a single class to handle both platforms using the separate Milkman ANEs in about ten minutes and I can use this single codebase on either platform with no changes to my code.
Milkman's ANEs are also a single up-front cost with the extension assigned to the developer rather than the client.
You have some nice goals for your extension and your Kickstarter price-to-own is low but I'm not impressed with your approach of pretending like the competition is worse than they are.
