Unfortunately, the images available through the Raspberry Pi Imager aren't correctly configured to use the 'official' Touch Display. This results in some fun visual effects followed by static vertical lines on the screen when, presumably, the OS stops driving the display. They look something like this:
Fortunately, in the case of the Manjaro distributions, the solution seems to be a fairly simple addition to
While I was at it, I also updated
cmdline.txt to set
console=tty1 to ensure I always get console output.