I managed to find a solution to use my android tablet as an external monitor for linux, like duet or WiredXDisplay on Max or Windows.
for those with Intel there is a great solution called virtscreen. NVIDIA and AMD users need a different solution
https://snapcraft.io/install/virtscreen/opensuse
adb reverse tcp:5900 tcp:5900
adb shell monkey -p com.iiordanov.freebVNC -c android.intent.category.LAUNCHER 1
xrandr --newmode "1200x1920_60.00" 196.47 1200 1296 1424 1648 1920 1921 1924 1987 -HSync +Vsync
xrandr --addmode DP-1-1 1200x1920_60.00
xrandr --output DP-1-1 --mode 1200x1920_60.00 --right-of HDMI-A-1
x11vnc -rfbauth ~/.vnc/passwd -clip 1200x1920+5760+0
These command worked well and very fast enough.
After some tumbleweed updates, it became unusable slow.
is there a way to get a faster x11vnc again?