From what I understood:
• You have stark scale differences between bottom and top levels.
• Due to the scale difference, absolute metrics like RMSE/MAE prioritize the top levels.
• You used SMAPE to help with the top-bottom scale difference.
• You wonder if there are weighted losses in NF
Answering the questions:
• Like SMAPE, probabilistic losses (DistributionLoss, PMM, GMM...) are scale independent by definition.
• Regarding weighted losses, check scale-independent errors and weighted MQLoss here is the
NeuralForecast losses catalog.
• Before ditching the probabilistic approach I recommend you to carefully explore:
◦ Use
HierarchicalForecast tutorial to set an accuracy expectation.
◦ Explore your forecasting features, control for seasonalities if any.
◦ Model hyperparameters (learning rate and random seed in particular).
Hope this helps.