Have T32 4 Motion that has had a lot of suspension work ( b14, uprted ARBs , 25mm wheel spacers ) carried out by Oli of Bognor Motors . He is increadably helpfull and knowlegable about all things T6 and was of the opinion that it was important for the 4Motion system that the wheels remained matched and in line . His advice in my case was to have the wheel spacers on all wheels and not just the rears which was my original request.
Not sure if that helps at all but Oli is contactable via the forum and will i am sure be able to help you out with the question .
Good luck either way
Adrian