Google the source for Arduino OTA. Thats what I did when I had the same question as you.
Since then I just rolled my own

Espressif has an example doing this. But its for IDF, should not be any trouble to get it working for Arduino
https://github.com/espressif/esp-idf/tr ... le_serving

In WLED settings web page choose "Solid" for the effect mode. Then for color choose black.
Then go to presets and save that setting as the preset. On boot it will run that preset, and keep them off

Get the Flash Download Tools.
https://www.espressif.com/en/support/do ... ther-tools

Yes & no. Yes it can be done, but no in that there isn't a pre-built solution. I have done what your asking but it came from putting together a few of their solutions. IF you want to do the same, you can start with this for getting access to a USB memory stick. https://github.com/espressif/esp-idf/t...

#define PIN_TO_READ GPIO_NUM_1

// If pin # is <32 use this
#define PIN_READ() (REG_READ(GPIO_IN_REG) >> (PIN_TO_READ));
// Otherwise, use this
#define PIN_READ() (REG_READ(GPIO_IN1_REG) >> (PIN_TO_READ- 32))


// Check state of pin here.
uint8_t busy = (uint8_t)PIN_READ();

have you looked at any of the examples here ?
https://github.com/espressif/esp-idf/tr ... rals/mcpwm

Strange to hear you had all those problems.
I have found using the Esperessif Extension to be problematic if say you have other Extensions installed say PlatformIO.
What I have done was use VSC portable. Then when I install the Esperessif Extension it goes smoothly.

Ok, we will give the GPIO0 a try. Thanks for the tip, and hopefully that works. Still though, a test rig would be a great tool to have for the S3.

Thanks. looks like more reading for me