At around this time the plant started to get deficient in Magnesium and Calcium. Most probably because substrate ph dropped below 6.
Nutrient solution was ph-ed to 7.5 for a little while, with some additional dolomite lime top dressing. Unfortunately in this critical growth phase Calcium deficiency can cause some leaf necrosis which will be visible for the remainder of the plants life.
Other than this the plant settled nicely into flower with very manageable stretch.