Okay - it's worse than I thought ......
printer perfect - but the mobile organic bifurcated interface is f***ed ;-)

Yeah, turns out I didn't screw the terminals down tight enough.
After re-seating and using the correct size screwdriver - everything now working perfectly.
I've even added the top extruder 'pyramid'.
This cuts the bowden tube length down by about half.
And eliminates any really extreme angles in the tube.
Hopefully this'll make it half decent for flexible filament

So everything is now doing everything it should, levelled the bed and am now looking for a simplify3d profile for it and coming up totally blank.

Thing is - does the slicer have to know it's a corexy ?
I guess I'll just have to make my own profile and see what happens :-)

Oh and I need to add another 20mm to the hotend cables, it's kinda tight at the front right corner.
I don't usually do proper cable management and I think i got a bit carried away lol

But yeah, so far - as with all my other printers, only issues have turned out to be my fault :-)

Oh yeh I buggered the print surface while making the levelling nuts so that they don't rotate in their sockets when levelling.
But have just swiped the aluminium with some magigoo - and that will most likely do a much better job anyway.

There are 2 sheets of pei the correct size in my workshop somewjere.
But I put them in safe places and cannot find them, not for love not money.
So magigoo and a slightly reduced print area it is for now.