Looking at the ride graphs his power target seems to be 250-280w range.
Is that for an FTP of around 400w?
There has been some discussion about ISM zone 2 fitting in with Dr F training (medio) and even sweetspot, but this is clearly much lower.
In the Sebastián Ziegler podcast on TTS he says that Fat max (ism zone 2 target) occurs, in his experience, around 1.1-1.3 mmol and 68% FTP on the thousands of athletes he’s tested.