The Number 1 CHT (C1 redline on bottom). Can't be correct as it is 75 deg cooler than the average of the other cylinders. Since the No 1 EGT (red line on top) is pretty close to the other cylinders I would say that the CHT probe on No1 has failed. As was pointed out the factory CHT ( ie the one in the panel engine gauge cluster) comes off No 1 so the first thing I would do is see what it shows on the next flight.
I am also curious that the EDM 700 does not have a TIT indication. That is how I lean these engines. That is just lean to a TIT value (1425 deg F for short trips 1500 for longer cruising at altitude) which is a quick and easy way, although individual cylinder EGT/CHT must obviously be monitored.
The big issue for engine life is keeping the CHT's down. From your graph the spread on the CHT's (No 1 excepted) looks good.
