I'm usually pretty methodical when brewing so I was just thinking of reasons why I might not get full attenuation.
According to my notes my mash temp was between 66-68c, which is apparently 150.8-154.4 fahrenheit.
I used my STC-1000 for the mash as well as for fermentation control, and it is calibrated against ice water and 2 different glass thermometers (themselves calibrated against ice water and boiling water). I only use the STC for the mash because it's easier to read from the digital display than the glass thermometers.
Thinking about it the reduction in efficiency is probably because I didn't squeeze the bag out as much as usual (this was a small batch BIAB).
Anyway, time will tell. The temperature was reading 23.8c this morning and the room smelled distinctly beer-y so we'll see.