I use dual display on Windows11 pc and iPad Pro(3rd Genesis).
If I move mouse cursol,iPad Pro’s sync is very slow.
If Compression Quality is down,IT’s as a same.
And, Framerate 30fps and SubSampling is 4:2:0 also are same .
Connection is Wifi ,Wifi is no problem.
Routers can cause lags and latency. Bypassing them always improves performance.
Configure Windows 11 PC or iOS device as WiFi Access Point (Hotspot) and connect to it before connecting spacedesk.
USB Tethering achieves the same result.
Please check the chapter “Performance Tuning” in the instruction manual: https://spacedesk.net/user-manual