Focal-plane-assisted pyramid wavefront sensor: Enabling frame-by-frame optical gain tracking V. Chambouleyron, O. Fauvarque, J.-F. Sauvage, B. Neichel and T. Fusco A&A, 649 (2021) A70 Published online: 12 May 2021 DOI: 10.1051/0004-6361/202140354