If you allow charging over only one of the connectors, customers will find that highly confusing.

If you allow charging the device over both, you have to be prepared for the case where people plug in two power sources (yes, some users will do that, if you give them half a chance).

I think your best bet would be to go for #2. I think that requires software (or maybe hardware) that reliably handles the 'two power sources' problem. I wouldn't run that on the main OS and CPU, so you need something else, maybe a single chip that drives two USB type C connectors. I guess those may not yet exist.

(That's quite loose thinking, so it may be hugely incorrect. Educate me)