I just realized that this tool I made might be helpful for people in here. I use it frequently when working with MCUs and Nextion panels.
By using my tool I keep both the MCU and Nextion panel connected to separate COM-ports on my PC. This way I can program them separately and when I want them to communicate, I just connect them through the proxy tool. It’s also possible to inspect all the communication between the MCU and the Nextion. I find it extremely useful for debugging.
Video example for data inspection:
Open source on GitHub of course: