Could you show us a block diagram as an eaxmple that what you want to do?
If so, we can figure out good way to you.
Since Type-C connector/receptacle does not have SPI line, you need to use USB Serial such as CY7C65211.
like this: SPI <-> [USB Serial converting from SPI to USB] <-> Type-C
Also, VBUS on Type-C has to provide at least 5V. Would it be a problem on your control unit?