I'd be interested in using this "app" but only if you would add the google 2fa. Simply because if the quoted does happen, you can't go crying to coinbase to get the "deal" reversed which depending on coin price you can easily lose money. Not just on say a dip if someone bought at $500 and you notice it at $450 but the money lost in coinbase fees and bank fees for transfers you weren't prepared for thus causing $35 NSF fees.
Just because the attacker can't get the coin doesn't mean they still can't fuck you over.
You need to look at the motivation though. What has an "attacker" to gain from buying coins on your account?
That being said, I will support any effort to add Google 2 Factor, the code is open source after all. Anyone who wants to look into this, I'll be happy to help you out.