You’re correct. While the stable version of KDE Wayland is usable right now with the new driver with no flickering issues, etc., it technically does not have the necessary patches needed for explicit sync. Nvidia has put some workarounds in the 555 driver code to prevent flickering without explicit sync, but they’re slower code paths.
The AUR has a package called kwin-explicit-sync, which is just the latest stable kwin with the explicit sync patches applied. This combined with the 555 drivers makes explicit sync work, finally solving the flickering issues in a fast performant way.
I’ve tested with both kwin and kwin-explicit-sync and the latter has dramatically improved input latency. I am basically daily driving Wayland now and it is awesome.
