Conference poster summarizing the results of Haxhijaj, Riemelmoser & Pasquarello, Phys. Rev. B 113, 104105 (2026). We benchmark the r²SCAN meta-GGA functional against PBE, SCAN, and HSE for the group-IV elemental solids (C, Si, Ge, Sn), assessing numerical stability, computational cost, and accuracy for elastic constants, phonon dispersions, and the α↔β phase transition. r²SCAN delivers lattice dynamics nearly matching HSE at far lower cost and is more numerically stable than SCAN, while being less reliable for α↔β transition energetics. DOI of the related article: 10.1103/znkf-3g37.