Finally took the roaster on the road and had some unexpected bad results; the ESP-32 kept seeming to randomly reset while in the middle or roasting. I initially thought the adjustable voltage regulator had dropped too low from it riding in the trailer while driving, but this proved to not be the case. Then it dawned on me... "I wonder if it times out when it can't connect to my Home Assistant instance?" Some quick googling and I confirmed that by default, ESPHome has a 15 minute timeout when it can't connect. Adding a single line to my 'code' to set this to zero fixed things and I've been successfully roasting coffee while on the road! Huzzah!