I built a version of this and it works great! I really appreciate all the work that has gone into the development of this project and it was amazing to find something that did most of what I needed for what I wanted to do. No more spam calls at night for me 
In my case I did not use a display and it was fairly easy to remove the display dependent parts from the code.
The only issue I had was with the ESP8266 crashing in the timer interrupt handler. I resolved this by editing SPI.cpp in the Arduino platform code and marking all methods in there with the ICACHE_RAM_ATTR. I've attached my modified file in case anyone else runs into this.
Cheers,
Rick
SPI.cpp (16.4 KB)