Looks like it should work. Your design has 4 capacitors, which is good. We've seen problems in the past where people didn't use capacitors, even some converters that said capacitors weren't necessary. They are needed.
I was thinking about naming some more, and I have a few naming ideas that won't conflict with the imxrt.h header.
For example, namespace separators ("::") instead of underscores.
I'm a bit concerned about this...
// Undefine anything defined by Teensyduino's imxrt.h
My guess is these .h header files are meant to be included only by the .cpp source files of libraries, right? But consider what happens if a library author...
If you only need the main processor, they're available from Digikey, Mouser and other distributors.
https://www.digikey.com/en/products/detail/nxp-usa-inc/MKL26Z64VFT4/4234818...
I hate this error because it's so vague. Here's example code that triggers it:
#include <Arduino.h>
static const char g_abc[] PROGMEM = "ab";
class foo {
public:
static const char& alpha(int x) {
static const char g_alpha[2] PROGMEM = {3...