This is actually one of the designs we use at work for building connector-only PCBs (like what you'd find in track lighting raceways) because our FR4 board used

This is actually one of the designs we use at work for building connector-only PCBs (like what you'd find in track lighting raceways) because our FR4 board used for that application is so thin that it can't go into the reflow oven, it will flex and slip off the rails when it heats up. We just make one big PCB with an array of connector-only parts and a track heater built-in, run the board through the solder stencil, pull it out, place the connectors by hand, slap the board on a lapped-flat granite block with a heater under it, hook up power, and watch it until it reflows. We use an extremely-low temp bismuth solder that reflows just a bit above water's boiling point for these boards. Nice to see hobbyists in the field coming up with the same concepts.