I've been up and down this road with Ardex. The NA can go onto a green screed no problem but then the contradiction is that they won't stand over it for tiling with Green screed adhesive due to potential shrinkage and although BAL is under the same umbrella as Ardex they have Green screed adhesive but no leveller that can go on a green screed and both of their tech departments won't ok me to use the NA leveller with the Green screed adhesive. So between the two companies which come under the same roof they have no soloution for levelling a green screed that can then be tiled before 3 weeks 😵