A Canadian developer criticizes a current limitation that does not allow him to run the animations in his app at the full 120Hz of Apple's ProMotion display, which is one of the most advertised new features of the iPhone 13 Pro and iPhone 13 Pro Max.
https://www.notebookcheck.net/Third-party-apps-apparently-can-t-fully-utilize-the-iPhone-13-Pro-s-display-and-its-120Hz-ProMotion-feature.565859.0.html