Touchpad Elantech ELAN1200 does not get disabled in tablet mode of Asus ZenBook Flip UX561UD convertible laptop

Sorry if acpid is not the right package for this. The blueprint for convertibles mentions /etc/acpi/twist-tabletmode.sh, though the blueprint is old and where this would be implemented may have changed:
https://blueprints.launchpad.net/ubuntu/+spec/client-1305-convertibles-and-touch-desktop

Repro:
1. Fold display back to tent mode and further to tablet mode

-> The touchpad should get automatically disabled, but doesn't. The keyboard does get disabled, and so the mode is correctly detected somewhere.

The touchpad CAN be disabled manually with the secondary Fn function of the dedicated key.

The touchpad is an ELAN1200 and the ELAN entries from libinput list-devices (under Wayland) are attached.

cat /proc/bus/input/devices gives:
I: Bus=0018 Vendor=04f3 Product=3066 Version=0100
N: Name="ELAN1200:00 04F3:3066 Touchpad"
P: Phys=i2c-ELAN1200:00
S: Sysfs=/devices/pci0000:00/0000:00:15.1/i2c_designware.1/i2c-1/i2c-ELAN1200:00/0018:04F3:3066.0002/input/input20
U: Uniq=
H: Handlers=mouse1 event12
B: PROP=5
B: EV=1b
B: KEY=e520 10000 0 0 0 0
B: ABS=260800000000003
B: MSC=20

kernel.org has this documentation about Elantech pads:
https://www.kernel.org/doc/html/v4.16/input/devices/elantech.html

Driver info on github:
https://github.com/mishurov/linux_elan1200_touchpad

Please let me know if you need any other info, thanks

ProblemType: Bug
DistroRelease: Ubuntu 18.10
Package: acpid 1:2.0.28-1ubuntu1
ProcVersionSignature: Ubuntu 4.17.0-9.10-generic 4.17.17
Uname: Linux 4.17.0-9-generic x86_64
ApportVersion: 2.20.10-0ubuntu9
Architecture: amd64
CurrentDesktop: ubuntu:GNOME
Date: Sun Sep 9 00:41:36 2018
InstallationDate: Installed on 2018-09-05 (3 days ago)
InstallationMedia: Ubuntu 18.10 "Cosmic Cuttlefish" - Alpha amd64 (20180822)
SourcePackage: acpid
UpgradeStatus: No upgrade log present (probably fresh install)