No, the problem is that the driver uses it's own API called EGLStreams instead of GBM, which everyone else (including Sway) uses. Open-source is not a requireme

No, the problem is that the driver uses it's own API called EGLStreams instead of GBM, which everyone else (including Sway) uses. Open-source is not a requirement for Sway support, just GBM support.