My that is pretty! I love how you can create what you need on a board. I still have not crossed over to that world yet. I really need to.
EDIT: Forgive my ignorance Jon, you lost me with rotating the 2nd digit to use it as a colon. I get why they have to be individually addressed to achieve that, but I might better understand what you are doing if I saw a rendered, drawing even, simple image of the expected output.
I soldered one of the displays together and it works.
This picture shows the back of the display. I forgot to order 2mm headers, so I soldered in a 6 pin pigtail.
Notice the position of the cable/connector. It's squeezed right against the side of the housing. This is where I made a small mistake. To ensure the header would fit, I shifted everything over slightly - 0.5mm or 1mm.
Notice the top rightmost segment - it's just under the edge of the bezel! My slight shift to provide room for the connector clipped the edge of this segment. Other digits in the same package might be a touch smaller and this wouldn't be an issue at all.
The display is entirely usable despite this small error, and it looks sharp.
I don't know if I'll use these displays for the next batch of timers, but it's an attractive option. With the acrylic panels, I laser-cut a rounded rectangle for each display and put a piece of 3M Vikuti Light Control film behind the panel to act as a filter. This film is polycarbonate and roughly 1/16 inch thick. I cut it to size on a paper cutter, peel off the protective film from both sides and adhere it to the panel with double-backed tape, all while ensuring I don't get any finger prints on the film. It's a rather tedious, time-consuming process done as part of the final assembly. A stack of pre-built modules would make the job easier.
I bought a couple of those volt meters and I think it's amazing that three 0.56" displays just barely fit. Anyway, I just ran across these three digit 0.39" displays on AliExpress that I think may be a better fit.