ReFusion 8B trained with ESPO mu=8 (ELBO-based Sequence-level Policy Optimization). Achieves 83.1% nonzero rate / 0.394 average reward on 124 test tasks (+22.6pp over SFT). Sequence-level RL with multi-epoch training (mu=8) and PPO clipping.
Paper
Concentrate or Collapse: When Reinforcement Learning Meets Diffusion Language Models for Web Planning
Dataset: FormFactory (992 train / 124 val / 124 test tasks, 25 form types, 8 domains)
Infrastructure: NVIDIA L40S (ReFusion) / A10G (FS-DFM) on Modal.com
Framework: PyTorch + PEFT (LoRA/QLoRA)
Training prompts: 50 (sequence-level), G=4 rollouts per prompt
Citation
bibtex
1@article{brillian2026flowgrpo,
2 title={Concentrate or Collapse: When Reinforcement Learning Meets Diffusion Language Models for Web Planning},
3 author={Brillian, Muhammad Enrizky},
4 year={2026}
5}