I know NebulaMiner is hard at work on a Rust implementation, but it sounds like it might be a bit. I think the best thing to do on that front is to get setup with the Espressif ESP-IDF SDK (it's C / FreeRTOS based). They have a bunch of cool examples for getting connected to WiFi and opening TCP sockets, etc. ESP-IDF has a cJSON library included which I think is the way to go for talking Stratum.
Sounds good; I've actually already played around with ESP-IDF on a regular old ESP32.
Rust dev is going from bottom up, so i am working on low level drivers right now. No project from existing template yet.