You can fix the flickering on Affinity on Linux using this env var: DXVK_CONFIG="d3d9.deferSurfaceCreation = True; d3d9.shaderModel = 1"
Combined with the patcher which fixes the problem that settings aren't saved, the only big problem left are the wonky path outlines
Recently found a search result which pointed to the Arch forums. Someone posted an explanation a few months after the last post for anyone finding the thread, and the only thing that happened was complaining about necroposting and spoon-feeding the solution, and the thread getting closed. It's really no surprise forums have been dying when miserable pricks like that are the ones running them