Retrieval encoders retooled for one-pass decisions: prior-fused heads hold up with scarce labels, cross heads win on full data
Biomedical retrieval sentence encoders can be converted into typed decision models that return thresholdable probabilities in one forward pass, with a cross head reaching 66–73 seen-task points, close to fine-tuned Laya-large at 75.0 with about three times the parameters.