Good for you, but I don't quite get the reasoning. I wouldn't expect any guarantee that Google will fund work on an experimental open source project indefinitel

Good for you, but I don't quite get the reasoning. I wouldn't expect any guarantee that Google will fund work on an experimental open source project indefinitely, or to pay for work they no longer care about. But why not accept funding on a temporary basis? When they get bored with the experiment and funding dries up, or they want to go in a direction you don't like, the source is out there and you could keep going on your own.