More than one factor impacts how much light a plant can receive per day (DLI - daily light integral) -- Temps and atmospheric CO2 being 2 large ones,
If it was only for the last little bit of light cycle, i wouldn't worry too much but keep an eye on it to make sure it doesn't get progressively longer, then feel safe
If it was droopy AF for hours before lights out, i'd consider riasing lights, dimming or reducing hours per day (no fewer than 15, if photoperiods). One, a combination, it doesn't matter too much
FWIW, 700-800 PPFD over 18 hous is too much without increased CO2 and a tightly controlling environment to match optimal feed to increased metabolism or some of that extra co2/light will just be wasted. 800ppfd over 18hrs is 51.8 DLI. 700ppfd over 18hrs is 45.4DLI - still probably 10-20% high,
So, i would guess you have droopy plants for a couple hours or so?.
if i am right, reduce hours or raise lights. It does not take much distance to affect DLI at canopy (inverse square law). If you run lights at night, reducing total length while providing same DLI does not negatively impact yield... common sense .. 1-to 7ish hours/day light-torching it will not work i'd guess, lol, and 24/0 has some less deadly drawbacks too. Anyway, these 2 otions are better than dimming in bloom. I'd rather spread teh photons out more (raising) or just run shorter period of time per day than reduce photons emitted by the light (dimming). It may be only slightly more wasteful and what isn't absorbed by walls only benefits the lower areas.
With ambient CO2 and an autoflower on 18/6, start at 35-40DLI (referencing table is 550-600ish PPFD) and then fine-tune from there based on observing plants. They always have the final say. 16/8 cycle would be roughly 40DLI with 700ppfd, for example. Might need 1-2" of extra height at 40ish and possibly a bit more of an adjustment than that..