Again, we don't need large sophisticated neural networks, small ones will do. Though at this point you're making more of an empirical test of already used pubkeys since the Y polarity of the entire public key space converges to 50%.
if do small one, neural networks
for who know about neural networks. you can do with you Nvidia CUDA GPU. you know already to do.
but still not yet have sample code on github for try and testing
but for who don't know must about neural networks
try AutoML Tables by google cloud
https://cloud.google.com/automl-tablesjust upload dataset to server and training, that easy to use without no coding
(other service both Microsoft Azure AutoML and Amazon AWS SageMaker have Automatic neural networks service same)