Personally, I wouldn’t jump to conclusions about light too quickly. Cannabis loves light very much, and yes there are diminishing returns from increased light levels.
However, from my experience It’s important to take a holistic approach.
There’s a very symbiotic relationship between plant environment above and below the root bed.
with increased light levels, the cannabis plant will be hungry for more frequent feeding and possibly even more nutrients than you might think, in order to conduct photosynthesis at the rate at which you are asking it to perform.
You might not necessarily be giving too much light. You just might not be treating the plant with the right support to chew through all of that light you’re throwing at it.
does that make sense?
All too often, a caring grower will see leaves like that and think “oh no, I’m giving it too much of this one thing” or “there’s a deficiency of ________” because of someone’s reply on a forum somewhere.
you sound like you have the Capacity to closely monitor what’s going on in your grow space. Sticking to an exact pH and EC as prescribed by people on the internet or your nutrient manufacturer is never, never enough to go by. You must consider everything at once and try to understand why the plant might be displaying signs of stress. It might really love your light. But it’ll get more thirsty.
Make sense?