Other PiBox / KubeSail cofounder here. I put in an enormous amout of time into designing around components that can be easily sourced and are stocked regularly. A good example of this is the SL2.1A USB hub we use. The datasheet is in Chinese, but after testing it on several prototypes, we saw great reliability for 1/10th the cost. And its always in stock. Currently Microchip USB hub chips are either out of stock everywhere, or cost $5+, which doesn't make sense for low-cost Pi accessories.

The only issue we still face is sourcing actual Raspberry Pi compute modules. There's very little we have control over there.