I had some yellow spots starting to appear in batches as well as a few dark brown spots after raising my lamp thinking it was due to light burns. After some research, it was most probably due to nutrient deficiency (most probably potassium deficiency). I moved my feeding schedule to the late veg quantities and that seemed to have stopped these issues from spreading. After a few days, they seemed to have receded as well.
I had to defoliate the lower level leaves again as more of them stopped growing and stayed in the shade.
I originally wanted to top twice, but seeing the secondary branches growing, I doubt I'll have the space for that 2nd top to go anywhere. I'll start ScrOG and see if that is necessary. For now, I'm only doing simple LST to spread the nodes.
Light from the picture will change on the 12th as I lowered the light a bit more now that I know the discoloration was not due to light burn.