kwin
Mouse Cross Border Lagging
Disable cross border for mouse when using multiple screens
Look for the section called [EdgeBarrier]
[EdgeBarrier]
EdgeBarrier=0
CornerBarrier=0
Also look for [Windows]
If it doesn't exist, scroll to the bottom of the file and create it. Add or change the value false and 0 as follows:
[Windows]
ElectricBorderMaximize=false
ElectricBorders=0
Reload kwin rules
qdbus org.kde.KWin /KWin reconfigure