Stair height & nosing when flooring landing?

Moving into a new build soon, would appreciate some guidance since we'll be doing the flooring ourselves.

We intend to put SPC /LVT on the 2nd floor.

The subfloor is Osb, and while it's level there is a bit of a lip between boards, including a couple of largish gaps. They're all fairly mucky with bits of construction mess left on.

I'd like to overply with 9mm boards ideally, or 6mm (after cleaning and flattening) just to give it a more consistent finish since SPC is only 5mm.

What I'm not too certain about is the +14mm where it meets the stairs.

What is an appropriate edging in this scenario as the stairs have a rounded nose? We hope to put a carpet runner later when funds permit if that changes anything.

Does the +14mm require other steps to have the height raised too I.e. To avoid tripping from slight difference, or do they make the last step a bit shorter to account for this?