I am currently setting up three headbands powered by Picos. The light weight strips I am using do not have the usual “spare” 5v and gnd cables that more robust strips have. As a result, I am having to muck about with cable joiners and such to ensure both the strip and the pico are powered.
It has just occurred to me that if that second row of solder points, if left complete, rather than snapped off half, would have made this job much simpler and cleaner - all the while those who wanted to wire a strip directly and use the “half” row to secure the first could still snap off that row with some shears or by scoring.
Those are “castellated” edges and are intended to make it easy to mount directly to the pads on an LED strip, which would leave the full through-hole for wires.
There’s any number of ways these could be used, but if you end up having two wires and no direct-solder pads, then there are still options. One is to twist the wires together, and solder them as one. You can also tack them on to opposite sides - the through hole can be filled, even flooded to include the castellated edge as well, and then tinned wires can be spot soldered to it.
Here’s an example, where the power wires use the through-holes, and the strip is using the castellated edge:
