(Semi) permanently disable touch input
Turn's out there's init.sh support on Lineage (content of /etc/init.d/90userinit):

#!/system/bin/sh
# call userinit.sh if present in /data/local

if [ -e /data/local/userinit.sh ];
then
   log -p i -t userinit "Executing /data/local/userinit.sh";
   /system/bin/sh /data/local/userinit.sh;
   setprop lineage.userinit.active 1;
fi;


So I wrote a bash script that removes the /dev/input/event3 on boot, thus It disabling touch input on boot time:

/data/local/userinit.sh:

#!/system/bin/sh
rm /dev/input/event3


If I ever need to re-enable touch input, I can simply remove the bash script.