No, I used the "regular" NeoPixels. The design is very similar to the boards of your modular clock, i.e. the neopixels are mounted in a PCB cut-out and soldered from the backside of the board. Using DSUB pins as socket, the filling tube does not reach into the cut-out of the PCB (at least for the IN-12s that I have).
I "copied" the board the hard way: re-designed it in Kicad since I wanted to improve my kicad skills anyways.
Just adding this FWIW - I seem to be completely inept at soldering the Neopixels so I removed them and used APA106 5mm LED's in place.
I also elected to use socket pins for the IN-12's.
Using the APA106's allowed me to position the LED right under the tube thus overcoming the issue of distance from the LED to the tube (which was even more in my case as I had used socket pins).
I am using V4 firmware but still cannot access the AP - I am dealing with that in a separate thread.
Here are some pictures of the APA106's installed in place of the NeoPixels - which I seem to be incapable of soldering!
I don't claim it to be a neat solution but it does allow you to get the LED nearer to the tube, which in my case (having used socket pins) helped a great deal.
Last edit: 1 month 1 day ago by Ian. Reason: Pictures inline