I haven’t finished running this workflow yet myself, but I wanted to note that you can check the progress of the Keras Network Learner by right-clicking on it while it executes and selecting “View: Learning Monitor”. On my machine (no GPU) it’s taking about 40 seconds per epoch, so this should still finish in under an hour.
Can you check this post to see if the suggestions help you? KNIME 4.1: Keras error ( Selected Keras backend 'Keras(Tensorflow)' is not available anymore - #14 by MarcelW