AFAIK in a weak NT setup, 2Nt here show a hand worth 16-17 pts, with 18-19 bal and a stopper north is too strong to bid 2NT. This mean that 2D need to be somewhat constructive and if you dont want to play game facing an opening of 18-19 bal you must make make the preemptive raise of 3D or pass rather than make the single raise.
However if your in a strong NT setup do you also play that 2D is somewhat constructive or that 2D can be trash ? If 2D can be bid with only 4 pts, it mean that opener will need to bid 2NT wide ranging. 2NT could be some offshape 16 pts up to 19 bal.
If your NT range is 14-16 what does opener do with 19 bal & a stopper ? Do you bid 2NT wide ranging or you simply GF ?
My poll question, assuming that you play 15-17 1NT and a jump to 3D is preemptive what the minimum for 2D here ?