Looks like both the Type A and Type C ports are running off the 19pin header... John, if it's convenient, do you think you can test the Type C functionality? We had some supplier tell us they couldn't do both a Type C and Type A off the 19pin. Ideally, test that the Type C and Type A both operate concurrently, and also that the Type C operates in either orientation (since it should be reversible).
I'm studying USB protocol for my thesis (currently doing) because I need to design a USB Hub with Power Delivery 2.0 through USB-C connector... Upgrading a USB 3.0/3.1 port to go through a USB-C connector is not a problem, as long as you provide a controller for this job and a MUX for taking care of double orientation for each port you want to upgrade (USB-A to USB-C)...
Just for example, you can have this "chain" of chips:
- your USB source, in this case that 19 pin, which provide 2 USB stream
- a MUX to select lines for USB-C orientation such as the Texas Instruments TUSB542
- a controller such as the STMicroelectronics STUSB4710 (if you need Power Delivery 2.0 - e.g max 100W through a cable) to address cable orientation (a line goes to MUX select pin) and Power delivery (if needed).
Cheaper solution may be the Microchip UTC2000. Still addresses cable orientation but doesn't provide as much power as the STUSB4710... Cheaper solution may be also possible but I haven't investigated so far as I need Power Delivery 2.0.
Anyway, Power Delivery adds complexity also because you have to provide DC-DC step-down converter to address differents Vdd (20V-15V-12V-9V-5V)... Except for complexity and higher BOM, there isn't any problem to upgrade a USB-A to a USB-C... Also, if you need video output from that USB-C... That obviously adds to the BOM... But for a simple USB-C with only data, upgrading from USB-A is a "kid play"