What we know from the AGM - Info from Storm_chasor, page-19

People are worried about the slab which I don’t think they need to be. Mark mentioned needing to change the attitude of the concreters, (I don’t envy him there) if a slab needs to be within a certain tolerance then that’s what needs to be achieved in order for the concreters to be paid the full amount, HX is going to be an expensive bit of kit sitting on site while someone else’s F’ up is rectified. Ironically when you mention 20-30mm out I think this is less of an issue, HX will have complete tooling capability, if the first row of block needs machined to match what’s on the ground I don’t see this being an issue. IMO