I agree but did he not already do this? (He got a third party involved who apparently 'strengthened' the tranny only for it to go limp again.
'I had no option to go third party and Gavin fixed my car in no time, replacing all remaining sensors just in case and applying more upgrades to gearbox -recommended by Martin from Willall to make it stronger.'
I also am looking to safeguard against a future tranny ailment (I have a 2011).
ps thats a hefty diagnostic fee for a tech who couldn't locate the sensors.