I see there is a setting under the Developer tab to unlock the bootloader.
Has anybody done anything with this?
There isn't a version of TWRP for this model so I'm not sure what can be done with that.
The BootLoader runs before the operating system kernel runs. Users can initialize the hardware device and create a memory space map, so that both the hardware and software are under an appropriate state. This is to prepare a correct environment for operating system kernel to be used.