AtomVM runs on esp32, right? It's not an ultra-cheap microcontroller, but it's pretty cheap. AtomVM isn't BEAM either, though. I have no experience with AtomVM though... it didn't seem like a good fit when I was building something with an ESP32 (I didn't see anything about outputting to LCDs, and that was reasonable with arduino libraries... I also saw a library for calendars and thought that would work for my needs and then I got dragged into making it work better), and it would have worked for the stuff i was doing with ESP8266, but I didn't know about it when I was shopping for boards, so I didn't want to pay extra.