Tabular MAE self-supervised pretrain lost to v3.3 (stratified F1 0.573 vs 0.729, LOCO 0.645 vs 0.870) — kept v3.3

We tested SSL pretraining (tabular masked-autoencoder, He/Bahri-style) on a 9,722 country-day unlabeled superset, then fine-tuned on the same 4,237 labeled rows v3.3 uses. Stratified 5-fold F1 0.573 (v3.3 baseline 0.729) and LOCO median F1 0.645 (v3.3 baseline 0.870). Both promote floors failed by wide margins. v3.3 stays in production unchanged. Second SSL-style negative result after TabPFN — pattern documented.