Possibly Defective Hyperpixel?

Trying to get this to work with my Pi400. The script gives me a grand total of 0 install options so I had to manually clone the pi4 branch and install and then… well the backlight on my display turns on and the touchscreen works (strangely) but I get no display whatsoever. Am I missing something? Is there some kind of diagnostic I can run to see what the deal is or adjust/confirm the config?

So I found the solution here, looks like the /boot/config.txt was missing one line: