There’s a ribbon cable tester project at https://github.com/tomarus/cabletester. I forked it and made a PCB for it, with a few minor modifications mostly to do with the ordering of the connections. Seems to work:
The intention is for the display to plug into a header on the board but it turns out these displays come in a couple of versions that look identical at first but have different pin ordering. Aside from that they seem entirely compatible. I didn’t notice until after I received the board and display and found they used different orderings. So I used M-F jumpers to connect this display. They’re cheap enough even from domestic sources (about $7) that I just ordered another one with the other pin order, and for future boards I’ve modified the PCB layout to have footprints for both. I also added mounting holes which were omitted in the first PCB run.
There are Gerbers in the GitHub repository: