Continuous post-training has become a central strategy for foundation models to incorporate new knowledge without losing already acquired capabilities. In this context, on-policy self-distillation has been presented as a promising solution to mitigate catastrophic forgetting. However, a recent study (arXiv:2607.01763) questions this optimistic view by thoroughly analyzing the method known as SDPO (Self-Distillation Policy Optimization). According to the results, when the teacher's signals are stable and well-aligned, SDPO can accelerate specialization in specific domains, but it suffers from severe limitations when facing scenarios outside the original training distribution. In continuous post-training, this technique shows more severe forgetting and can even collapse, while on-policy reinforcement methods like GRPO adapt more conservatively and better preserve prior knowledge. Furthermore, the analysis reveals that denser self-distillation causes greater drift in both parameter space and response space, and can amplify high-frequency format artifacts through a teacher-student reinforcement loop. These findings indicate that on-policy data alone is not sufficient for continuous learning: dense self-distillation can be useful when the teacher's objectives are stable and token-level supervision is reliable, but it should not be applied as a default stabilizer.
For companies working with artificial intelligence models, these findings underscore the importance of designing post-training strategies that balance specialization and generalization. At Q2BSTUDIO, we understand that each project requires a customized approach; that is why we offer AI for businesses that integrates advanced optimization, adaptation, and deployment techniques, always from a practical and scalable perspective. Our custom applications services allow organizations to build robust solutions that incorporate language models and AI agents, minimizing risks of forgetting or degradation. Additionally, we complement these capabilities with AWS and Azure cloud services, cybersecurity, and business intelligence solutions like Power BI, ensuring that infrastructure, security, and analytics accompany the model throughout its entire lifecycle.
The main lesson from this study is that, in continuous post-training, denser is not better. Companies must carefully evaluate when and how to apply techniques like self-distillation, and rely on technology partners that offer custom software and machine learning expertise to avoid falling into superficial optimizations. At Q2BSTUDIO, we combine deep technical knowledge with a results-oriented approach, helping to transform artificial intelligence into a real and sustainable competitive advantage.

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