Debug Wio LTE JP with VS2019 and vMicro

Hi, ALL

I’m totally new to Arduino.
I would like to debug Wio LTE JP board (CPU: STM32F405RG) with VisualStudio2019 + Arduino IDE extension from VisualMicro (vMicro).

Could you kindly help me?

(1) This board has one USB port. Debugging using such as breakpoints, step by step execution, valuables watch etc. is possible with this board using one USB port?
(2) This board has DFU function (Device Firmware Update). I understand that the board need to be switched to DFU mode when a program is loaded and need to be normal (running) mode when the loaded program runs.
How and when DFU mode and normal mode to be switched?

Thank you very much for your help.

Masay