GPIO power source with USB-C OTG, any power issue?

I am planning to use the USB-C OTG function of my ROCK 5 Model B to communicate with my computer. I plan the power the ROCK 5 via GPIO as I intend it to function even if the computer is switched off.

Will double powering by USB-C + GPIO create any issues? Or will the GPIO power create issues to the unpowered MP8759 (between type-c port and VCC 5V) when the computer is switched off? There seems to be no diode preventing reverse current flow into MP8759 from VCC 5V.

Thanks

I have not intentionally done this with the Rock 5 but I know you can do this with the raspberry.

I was building a power supply to power the Rock 5 and through GPIO 5v rail along with several external components. I wanted to compare it to a PD power source so I unplugged home made power supply but left it connected. When I plugged in the PD I noticed that the light on the power brick attached to my home made power supply lit up. I ended up adding diodes to prevent power from flowing into my home made power supply from the rock 5. While I tested to see if would boot without frying my board, I didn’t test it further. I ended up getting a USB-C splitter that split the USB-C into a PD port up to 100w and an OTG port.