I like that it is pretty directly written up, and doesn't speculate as to why. Some of the choices they made appear to baffle the original author:

  Looking at the circuit now, before anything else: I honestly have no idea why the SBU pins on the USB C port are connected at all. Chargers don't use them, and they definitely shouldn't be shorted to the CC pins via R2 and R4 like they are. They won't mess with the charging process, but they could hurt some other obscure devices if you tried to plug them into the RG35XX Plus.

And this one:

  I'm honestly not really sure why the custom circuit is used when the AXP717 chip supports proper control of the USB port pins - my guess is that this requires the firmware to communicate with the AXP717 to do it, and that software development might not have been done by the time the PCBs were manufactured. It does mean that given firmware support, a small component change could fix the problems I'm about to describe though.