I've been meaning to share this for a while, but always put it off. A few years back I wrapped most of the ESP-IDF in Nim for an ESP32 project for a startup. I had to add FreeRTOS to Nim's standard library to get networking which was surprisingly easy. I've had production firmware running with this for a couple of years now. It's been pretty great and very stable. There's at least one other commercial user floating around.