Got the button/display board built last night. I was able to add the pin header to the main board with no trouble. I did them after I had done all the soldering on the button/display board, so I was fairly comfortable with the soldering. After downloading the software twice to get the correct WIFI id it seems to be working correctly.
Now on to printing the case and fan housing and getting a fan and servo. Then adapting it to my smoker and hopefully, I'll be all set to go.