short sum up:

-> a X input device sometimes have a different /dev/input/eventX number in between restarts
-> should this number change (I never noticed this before)
-> how to make it persistent?


longer more extensive description:
xinput /dev/input/event* number persistance
I have a rather complicated desktop config (advanced kioks sollution with 4screens, only on of them not being a touchscreen). Two are exactly the same (Same model, vendor, etc).
After going through hell and back to actually make them work correctly and properly calibrated I still have a big issue:
I have a script that recodgnises(from xinput --list-props) them and assignes each of the identical touchscreens to appropriate video heads (having a 50 chance of success I also have a procedure to flip them but that's beside the point), but sometimes the number on /dev/input/event* changes resulting a touchscreen having the default transformation matrix (making it useless)

extra problems: I cannot use udev to match serial number and assign a device name statically- we are talking about hundreds of machines, I need this automated. I cannot use udev to match specific usb ports for those touch screens as the manufacturer of the hardware/kioks assembly will not ensure usb plugs order(differnt company).

xorg config fragment to ilustrate (vendor obfuscated)
{code}

Section "InputClass"
Identifier "calibrationiB"
MatchProduct "XXXX"
Option "Calibration" "2188 14444 14019 2438"
MatchDevicePath "/dev/input/event9"
Option "TransformationMatrix" "1 0 0 0 0.267326732673 0.267326732673 0 0 1"

EndSection

{code}