If they stated that then their remap is entirely based around a fueling to get bhp technique, which is as old school as it comes.
Yes the 06 td4 brain only has about 56k as the actual source of ecu code but it's amazing how dynamic it can be adjusted.
Give the guys at
http://reidyremaps.co.uk a shout, matt is your man and he will tell you your local agent.
Him and a guy called Mark basically created the digital rover and also land rover tuning scene 15 years ago, mapping vis obd 1/2 when people claimed the ecus where impossible to code etc. Dual mapping, triple mapping, mafless etc, they lead the way.
Almost every generic remap file since the late 90s / early 00s related to anything 4 cylinder land rover / rover petrol / diesel and 6 cylinder rover petrol can be traced back to them or their techniques have been duplicated, most of the time the people selling them don't even know they are using it.
Its all I run on all my cars, from my race tuned Mg 190, to my rover 75 tourer diesel running 24 psi with map, injector tweets and even a hardcut on the file for the crack and was coded for mafless running, 250k miles in her now with 145k of them with the maps. Along with my wife's car.
Alas the td4 hasn't been done yet due to other demands, but I know the team I will be going to.