FP4 Explore, BF16 Train: Diffusion Reinforcement Learning via Efficient Rollout Scaling. - Yitong Li; Junsong Chen; Shuchen Xue; Pengcuo Zeren; Siyuan Fu; Dinghao Yang; Yangyang Tang; Junjie Bai; Ping Luo 002; Song Han 003; Enze Xie (CoRR, 2026)