Beyond Full-Model Rollback: AuroSFT for Adapter-State Multi-Task Fine-Tuning

Yue Han; Ziniu Liu

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arXiv · 2608.05250

Beyond Full-Model Rollback: AuroSFT for Adapter-State Multi-Task Fine-Tuning

Yue Han·Ziniu Liu

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Abstract

Multi-task supervised fine-tuning (SFT) often casts a heterogeneous data mixture as a single optimization problem, even though different tasks may reach their best generalization at different times. msft exposes this mismatch through task-wise roll-out, exclusion, and rollback, but its original formulation materializes the scheduler state as full-model checkpoints, making stage transitions costly to store, restore, and deploy. This paper introduces AuroSFT, a parameter-efficient framework that recasts the carried state of overfitting-aware multi-task SFT as a compact, mergeable adapter state. AuroSFT freezes the pretrained backbone, trains only injected adapters, rolls back adapter checkpoints at task-wise peaks, and continues on the remaining active mixture. At the layer level, each adapter applies an AuroRA-inspired adaptive nonlinear layer to a low-rank weight factor rather than to the sample representation. The resulting update remains linear in the input, rank-bounded, and exactly mergeable into the frozen projection. Under the retained-backbone comparison protocol, AuroSFT achieves 61.36% average accuracy, compared with 59.85% for the corresponding msft reference row, and obtains higher accuracy on all five backbones. Our code is available at the anonymous repository: https://anonymous.4open.science/r/AuroSFT-80D1.

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Yue Han, Ziniu Liu. 2026-08-05. Beyond Full-Model Rollback: AuroSFT for Adapter-State Multi-Task Fine-Tuning. https://arxiv.org/abs/2608.05250

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