@DJW @JayEmm
See reply from Dave @Hangar 111 regarding Komotec's response when asked about the 460. I have no interest in taking my car on track so fast road use will be ok.
So I managed to ask Daniel the question directly… what he said was that on the Exige IPS cars, they have not had any problems with 500nm, it is only the earlier Evora that have issues. He believes that the hardware/software has been revised, which seems to handle it better. The torque converter is ultimately the limiting factor, under hard use it can overheat and essentially cause slip. He also said that renewing the transmission fluid on a much more regular basis seems to help – he had one car which was not shifting correctly and generating TCU fault codes, they changed the oil, and it was OK again.
So, in conclusion, from what KT are saying, it should be OK, particularly for mainly road use where you will not be generating the same sort of prolonged hard use.