Do you have any interest in this, Jason? I saw that you maintain the other keras-* stuff. Otherwise I'd like to play with it, so I can take a shot at an ebuild.
Nevermind. I was hoping to avoid TensorFlow, but it looks like Keras development has already stopped and the (now-TF-only) high-level API is built into TensorFlow-2.x. Such is life. Theano is also dead, and in usual Facebook fashion, the only way to install PyTorch is to `git clone` fifteen projects manually. Against all odds, TF is the winner.