I'm 99% sure the leaf curl is just a lot of nitrogen. You're almost there man. If you flush the plant you're going to start seeing deficiencies. I understand you gotta do what you're going to do, but just keep giving them bloom nutes until harvest.
Flushing is just gonna starve your girl resulting in less weight. The leaves would yellow but the calyxes are unaffected because the plant preserves those cuz seed is the only way a plant can live forever.
..... It's like if you put a person naked out in the snow. The body shuts down the limbs to keep the torso alive, dig?
Flushing to correct salt buildup could be useful (I understand that's what you're doing), but late flower flushing brings on disease.