Sorted, I don't know if this will be any use to anyone but my door is a CDS one (Composite door solutions)
Tightening the 3 hinges with a 4mm Allen lowers the door, mine was hung too high and was clipping the top brush strip on closing, especially after adjusting the bottom hinge. What I then found is the door would go longer lock, this seemed to be because one of the multipoint locks was not engaging properly in the keeps now that the door had changed position.
Removed top and bottom hook keeps, the door then locked properly. Refitted the top keep, still locked properly. Refitted bottom one, and bingo. Couldn't cock the handle up so I could lock the door.
As I'd dropped the door, I repositioned the bottom hook keep down slightly. Tried again to lock the door and it was perfect.
There's a fine tune adjustment on the hook keep done with a torx head that allows a snug fit. Played with this a few times until it no longer locks, then adjusted back only just enough so it actually does lock. That way I get a bit more compression when the door locks shut.
I'll check in the day light but it should be much better at the bottom edge now hopefully. When it's shut and I kick the bottom corner there's hardly any backward or forward play now. Good sign.
My original fitters never returned my call, surprise surprise. Doubt they'd have spent the time and effort tweaking it to perfection, mind you.