A couple of quick thoughts about the UART:
- Are you sure you have the correct RX connection (on the Savant)?
- The device may not echo, you’d have to turn that on in your terminal
- You might need pullups enabled ) enable them with capital P before running
bridge
For finding JTAG, I know @ian was working on getting BlueTag included in the build. blueTag (JTAGulator alternative) port to Bus Pirate