ONE-Core: Evidence-Gated Coordinate Search for Time-Series Inductive Biases

Architecture comparisons bundle observation, temporal, channel, capacity, and objective-side inductive biases, making whole-model winners difficult to interpret or transfer. We introduce ONE-CORE, a factorized testbed that audits one mechanism-linked bias coordinate at a time. Matched interventions measure its response, direct training-data descriptors propose where that response may change, and nested leave-one-dataset-out evaluation admits conditioning only when it improves on a fixed prior. Unsupported updates abstain locally; joint updates require a measured endpoint. Forecasting and remaining useful life (RUL) exhibit different compression preferences within the audited settings: a six-dataset forecasting audit retains a hierarchical prior, whereas C-MAPSS favors a compact single bottleneck before conditioning capacity. For MSE forecasting, a normalization gate reduces mean regret from 10.15% with fixed RevIN to 2.11% across twelve nested-LODO folds, with selective improvements on two folds. An in-family RUL capacity gate reaches 0.00% regret versus 2.66% for fixed dim16 across four C-MAPSS subsets; external bearing audits provide only directional corroboration. Anomaly detection (AD) instead audits readout, evidence source, and calibration. Its six-source diagnostic envelope reaches 0.438 macro oracle Best-F1 versus 0.412 for the best fixed source, but five datasets do not support a routing gate. These outcomes provide local design evidence with explicit scope and uncertainty, rather than a global architecture oracle.