The non-Lazer client works great under Wine! I used a 32-bit prefix, installed dotnet48, and osu! was good-to-go.
Latency and A/V sync all feels good without needing to tweak anything. I'm using evdev for my CTH-470, but there's a cool Option with the wacom driver where you can have finger touch and the whole tablet act as Absolute mode (instead of drag-to-move traditional touchpad; finger as stylus).