Replace a single neural representation of a rapidly oscillatory PDE solution by a macroscopic network plus an explicitly oscillatory corrector network. Feed the network both the slow coordinate $x$ and fast coordinate $y=x/\varepsilon$, and train the resulting composite field in a variational energy objective. This targets the paper's scale-robust approximation bound rather than forcing the optimizer and finite sample set to discover oscillations of wavelength $\varepsilon$.
Train a neural surrogate to predict outputs in a source-domain ZCA-whitened space, then adapt to a shifted domain using only the shifted domain's output mean and covariance. At inference, transport the network prediction through the target covariance square root, yielding a weight-free correction that preserves output-coordinate semantics and can be applied to MLP, CNN, graph-NN, or transformer regressors.
Couple the number of operator training pairs to the output resolution instead of increasing the output grid independently. Refine the output discretization only while the oracle reconstruction improves, and increase the training set when the learned predictor remains substantially worse than the oracle decoder.