I used a measurement of 10mm up on the metalized tape to punch the hole. That is the distance from the bottom of the "U" of the bubble sensor up to where the hole is over the photo transistor.. Here's a picture that might help. The edge of the foil went into the bottom of the U of the photo...
Ha... Brewer's Friend logging is working now. I think the problem was that Brewer's Friend limits logging to once every 15 minutes. I had mine set to 15 minutes, but maybe my clock runs a few seconds faster than theirs...
In any case I have logging set to 20 minutes now and have a first value...
Just flashed the latest 2.2.3 version using an HP Chromebook in Linux mode, using the esptool...
For a chromebook... "sudo apt-get install esptool" does the tool installation... You'll need to allow access by linux to the serial port once you plug in the 8266.
I used aluminized HVAC duct tape...