So, here's the thing:
On the downloads page there's a .tar file with a script that basically sets up the screen for you: tar file
The script for this particular screen is the "MHS35-show" one, and when opened in Vim you'll see the install steps it takes. Overlooking the horrible script job they did one section is of interest:
sudo cp -rf ./etc/rc.local /etc/rc.local
sudo apt-get install git cmake -y
sudo rm -rf rpi-fbcp
sudo git clone https://github.com/tasanakorn/rpi-fbcp
sudo mkdir ./rpi-fbcp/build
sudo cmake ..
sudo install fbcp /usr/local/bin/fbcp
There it points you to a github page to install the Linux Framebuffer drivers for small TFT LCD display modules. They are available in the kernel but I guess not loaded by default since most people just rather use their Pi with a monitor rather than a small screen.
Not sure if the Manjaro Kernel has them by default though.
The only part on the script I don't quite understand is the use of an "inittab" and "rc.local" file. Being that Arch/Manjaro and even Debian now use systemd don't see the need for it. Systemd handles all aspects of the system as far as i know.
Anyhow, still tinkering with the screen, see how it goes