Just in case you were unaware, the RP2040 is available on dozens of ready-made, arduino-compatible boards like the Pi Pico, the Adafruit feather boards, of the Seeed XIAO RP2040 boards. Those have all (or at least most) of the IO already mapped to pins, USB headers, booatloaders, reset buttons, etc already mapped.
Things like the Pico are really easy to solder onto a designed PCB as well because of the castellations, so it's easy enough to design a board around the footprint and then just solder the entire pico onto your PCB with a soldering iron, avoiding the need to use something like a hot-plate or reflow oven. This has been my preferred way of working with it.
He's acknowledged some of the short-comings of the most recent iteration of the doughnut tutorial on twitter before. Blender 4.0 should be coming out later this year and he's stated he'll be releasing a new version then: https://twitter.com/andrewpprice/status/1631529825717604353
Not sure about his more recent content but he used to have a policy that the VODs could be uploaded in full as long as they were uncut and not modified. If you go watch some older VODs he says so at the beginning.
I'm a casual embedded-electronics user at best, most of my projects haven't advanced much past turn a simple servo, light some LEDs, maybe read a sensor and POST to an endpoint. For these tasks, Arduino has been pretty good for me and removed a lot of the complexity. The `setup()` and `loop()` model makes a lot of intuitive sense. That being said, I've spent no small amount of time on `String` vs `char*` (as an inexperienced C/C++ developer) and found the guardrails of the Arduino ecosystem to be very frustrating.
Do you have any recommended resources or additional search terms to explore to learn more about hobbyist-level embedded electronics outside of the Arduino ecosystem? FreeRTOS looks interesting but it seems to add a lot of overhead versus something simple like Arduino. Similarly, I've looked at STM32 programming before but my searches were very generic and the STM ecosystem is massive. Specifically, I was trying to figure out if I could reprogram some old drone flight controllers (equipped an STM32F103CBT6 with a bunch of useful embedded sensors, running old versions of "betaflight") for personal projects but the entrypoint to STM programming (STM32Cube?) and the setup code was considerable.
Things like the Pico are really easy to solder onto a designed PCB as well because of the castellations, so it's easy enough to design a board around the footprint and then just solder the entire pico onto your PCB with a soldering iron, avoiding the need to use something like a hot-plate or reflow oven. This has been my preferred way of working with it.