Looks like the resistor(s) are actually inside the AnyWay box, instead of the usb-c plug.
As you can see in the pinout diagram, line CC is connected to the DB25 header which in turn connected to the box.
So, if anyone has the AnyWay box, the usb-c test cable, and an ohm meter they can simply measure the resistance between ground and pin 23 of the DB25 header. This way we could replicate a test cable without the expensive test jig.
I have played around with the "standard" test resistor values (300k, 523k, 619k etc) between line CC and Gnd, but wasn't able to get any results, not even download mode using a 300k resistor which works on all micro-usb phones. Either usb-c is using different values or there's something else we're missing here.
However, an interesting observation I've made, is that when flashed with combination firmware, the phone accepts most of these low level uart/modem test commands through the usb-c modem port (not the usb-serial port!) via a standard terminal (sometimes they need to be sent a couple of time for it to take, and also dialed *#0*# for test mode):
AT+GMM (Model number)
AT+HWINDICK (CPID S7 and newer)
AT+DEVCONINFO (Long info)
AT+FACTORST (Warning: Forces a factory reset!)
AT+FUS? (DL mode)
AT+GSN - IMEI
AT+SIZECHECK (Storage info)
AT+SIZECHECK=1,0 (Storage info)
AT+SVCIFPGM=1,1 (Short Info)
AT+<command> - read
AT+<command>? - read
AT+<command>=1,0 - read
AT+PRECONFG=1,0 - reads CSC config
AT+<command>=2,<info> - write
AT+PRECONFG=2,XAS - writes CSC config
Hope someone steps up to the plate, and gives us the correct resistor value between CC and GND on usb-c
Thanks in advance.