LongEval: A Comprehensive Analysis of Long-Text Generation Through a Plan-based Paradigm. - Siwei Wu; Yizhi Li; Xingwei Qu; Rishi Ravikumar; Yucheng Li; Tyler Loakman; Shanghaoran Quan; Xiaoyong Wei; Riza Batista-Navarro; Chenghua Lin (CoRR, 2025)