Hi Eric,
I just finished an app that uses your Unity plugin and I made some fairly significant changes to unify it into a single API for both Android and iOS. Would you like me to submit a pull request on the GitHub site with my changes, or are you already doing this as well with your revamp? Sending you my changes might not be that useful if you're significantly changing the API.
Also, the iOS version of the Unity plugin didn't have support for "bottom" banner ads (it ignored the bool passed in for positionAtTop) so I added it in a fairly limited way for my particular use case. I can send that along too.
Andre