First ever grow autoflower

I am getting amazing growth. The plants have doubled in size. I have noticed some bottom leafs are twisted. And there's some discolouration of the leafs. I'm not sure whether this is nutrient burn or nutrient deficiency. The plants are growing outwards and are now growing Into the tent walls. I was planning on using deflation methods but have since heard not to bother with doing so on autoflower plants. Despite the growth there are a few concerns. I reduced magnesium from 1ml per litre to 1/3 magnesium on the last feed, and I am noticing more blemishes on the leafs. Possible magnesium deficiency? I am going to flush the plants with just water and magnesium after today, unless research tells me otherwise. I feel like something needs to be done to keep this grow semi successful.