leaf tips bronzing all over

Is your humidity really 70RH%? During flowering that seems detrimental, where is the sensor that is reading the humidity? if it's at the bottom or middle of the grow space and reading 60-70RH%, the humidity higher up can easily be 20-40 higher, the plant will effectively close its stomata on the back of the leaf as its effectively too wet to "breath", this grinds photosynthesis to a halt, water uptake stops, root zone starts to sit possibly damp, lack of photosynthesis will force the plant to cannibalize its own chlorophyll which is the lightening of leaves rather than discoloration via sickness, the edges of leaves slightly tipped up suggests an inability to perspire causing heat exhaustion also, make sure top of the canopy is not over 86 Fahrenheit as she looks to have stretched very well. Could be as simple as that tbh.