Looking at the data post a recent tune of the car, notice some irregularities with the EGT's and a voltage drop under load.

Final dyno (roller) pull

EGT's for cyl 1 and 2 have some 'dips'. Looking back over previous data this was not present. The major dip is only for 0.049 seconds... Plus it is the raw data, not smoothed. The issue is not present when not under load.

this could suggest an injector issue or a spark issue. If the cyl is cooler then it could suggest that all the fuel being injected is not being burnt. Since the plugs were brand new then this could be eliminated. I'm yet to do a compression and leak down test, however the injectors are being cleaned. Plus, I need to check the connectors to the EGT CAN module.

Interestingly, this issue raised another one...

There is a voltage drop (as measured by the dash) when the car is under load. If the EGT drops were electrical it would be seen in other sensors.

A little more reviewing of old data, this is from the same track (approx same dates) over 3 years, with the same battery... again the voltage drops are there under load. I think that this suggests an alternator issue, happy to get some other thoughts as well.