Prototype board with integral power supply

Got tired of running multiple wires from bench power supply to my prototypes every time I started to work on something, so I put together this integrated unit. It features 3 different VCC supplies, each with its own voltmeter, and a useful drawer for keeping the wires handy. It's powered by a 12V wall adapter with standard 5.5x2.1mm barrel; they are cheap from Amazon, ebay or Ali. I May have gone overboard for many people who don't need 3 different voltages on their prototypes, but using relays and different Arduino setups, I found this worth the trouble.
I planned on using 5mm magnets to hold the drawer in place (hence the 5mm indentations in the drawer & the taps on the inside), but I found the magnets to be too far apart, and the drawer stays in nicely without, so it's up to you. The drawer fit is snug for that reason, and you may find the need to do some post-print trimming to improve the slide.
The back uses 7 M3 heat inserts. You'll also need 7 short (8mm) flat-head M3 screws fo