CC3220S-LAUNCHXL: UART serial from only JTAG connection possible?

I have a custom CC3220S board. It has both UART and JTAG headers.

I would like to connect only the JTAG header to the development PC ( via a XDS100v2 debug probe ) and

1) monitor UART while I debug;

2) flash new firmware using uniflash

Are these possible?

I have enabled "VCP" on both of my XDS100v2 channels and can see the corresponding USB serial ports are available from my "Device Manager". However, I cannot see any output from the serial ports while my program is running and uniflash also fails with a timeout error. When monitoring the serial ports, I have tried all available speed settings from 115200 down to 9600 8n1n.

Am I exceeding the capability of a JTAG connection?

I can, otherwise, debug OK with the JTAG connection and CCS7.