Cited passages: Appendix A, equations (A.10)–(A.13), printed pp. 26–27: entropy of group sums, entropic Ruzsa distance and triangle inequality. The inspected version is arXiv:2311.05762v2 (12 December 2023), in characteristic two.
Theorem 2.10 gives the approximate-group structure theorem. Corollary 11.9 and its proof, pages 68–69 in the inspected author version, obtain a bounded-index finite-by-nilpotent structure from one-scale relative polynomial growth. The proof uses a smaller scale with bounded growth; fixed scale constants may be adjusted by increasing the threshold.