I’m sorry, I’m reading this again. You haven’t finished the documentation. I would love to help you write the documentation if you can spare the time to explain how to do this. I like think I am a good test candidate because I have been programming for decades, worked as a systems engineer, and, most valuable of all, I am retired and have lots of time.
And I far from an expert in platformIO or visual studio, meaning I will ask lots to stupid questions! ideal for documenting everything you need to know to make this work. Already did a write up for this particular piece of hardware here, based on the Arduino IDE.
Based in Europe, so would need to be CET, assuming your in the US.