Trusted engineers get to take home prototypes. Usually also loaned a maxed out Mac Pro so they have something with enough memory to unpack MacOS's built in system process recording mode. (digging through a 5 minute recording of MacOS took ~~200GB of system memory to unpack and evaluate.)
I assume by your answer that you work at Apple or know someone who works there so let me clarify that I'm talking about the messy work that happens before you have a take home prototype for a device. I'm talking about building the prototype with in-house machinery before asking the manufacturer to make samples at the factory. If you do work at Apple, do you hand assemble prototypes at the office or do you just ask the manufacturer to build them and overnight them to your house? If so, do you have lab equipment at home to inspect and test it?
