Tom Chai

Is this the same bottom cover as the AirPort 802.11ac?

This is freely replaceable, no special lockdown present.

To be honest I don’t this is “almost impossible to replace. It is literally right in the center once your take off the screen.

Also it doesn’t seem to cause the device to brick either. Most of the time you get inaccurate clock whenever you unplug the computer from power and that’s it.

Probably not for redundancy, but for capacity.

CR2032 is too thick for this model, so they used 2 CR2016s instead, more or less the same thing.

Those are likely to be hardware debug leftovers, or devkit leftovers. Extra hardware features are needed for game developer kits, like a CMOS battery, extra buttons and displays for example.

Xs has 4 antennas, while the XR only has 2.

Easy, you are supposed to desolder the battery and the dock flex first, remove the logic board then access the battery.

Look at the CPU heat spreader, it is much thicker than previous models, is it possible that this is some kind of mini flat heat pipe?

Yeah it is just a case ventilation fan, it doesn’t blow any heatsinks directly. Although with the very low TDP of the processor, a case fan with radiator type heat sink should do the job.

It is not possible to access the internals from the back, the back is locked to the case with screws from the inside.