The first ECU queried in the short-test is VG, or the transfer case ECU. The exclamation point to the right is telling us that SDS can't communicate with it!!! Also, most of the CAN codes are CURRENT, which means the problem is happening NOW!!! A simple CAN voltage test is the first thing that needs to be done. With the key ON, the CAN H should be around 2.6 volts and CAN L around 2.4. If not, the VG should be disconnected (it's under the center console to the rear of the shifter), and the voltage re-checked. I'd also look very closely at the wires going to the transfer case motor. I won't go into too much detail. The dealer guys should already know this, or at least one of them should.

This isn't really that complicated a diagnosis. There must be more to the story though. The short-test is quite clear as far as I'm concerned.

I agree it is quite clear the CAN has crashed and they probably shouldn't be throwing these parts at it until it's certain why the CAN is down.

They have no idea what they are doing.

BTW:

Both CANH and CANL should be at 2.5 volts when not active, but can be up to 0.9 volts apart from each other.

CANH active should be between 2.75 and 4.5 volts.
CANL active should be between 0.5 and 2.25 volts.