For what it's worth, mine shipped with the same default setting of -1.4. I had the same question in my mind but deferred to the video instructions and made the adjustment to -1.0. I will be watching to see what Reiss has to say.
Tony Cordery wrote: I do however have a question which I would imagine is, best directed at Reiss.
There are several references here on the site to keeping the Offset value set at -1.0 and it is a point stressed in the retro-fit installation video. My machine has arrived with an Offset of -1.4 Is there any reason why this would not have arrived factory-set at -1.0 and, should I now reduce it ?