Matched evaluation finds DPO leads overall on safety control and text monitoring, while representation probes stay competitive at far lower marginal compute
Under one matched setup, this work compares behavioral safeguards (DPO alignment and text monitors) with representation engineering (three steering methods and four probes), finding that DPO gives the strongest overall control and improves with more training data but can lose safety after benign fine-tuning, that specialized text monitors achieve the strongest detection accuracy, and that representation probes remain competitive at substantially lower marginal cost when reusing native activations, with probe-guided interventions recovering much of the safety DPO loses after benign fine-tuning at little added over-refusal.