Kushberry X Gorillabomb Main-line

That should be fine as long as you have plenty of airflow mate. My rh about the same and temps about 19C lights out...0 problems and close to chop.

Your plants look healthy but the last picture maybe slightly indicative of a mag def, see how they do with your new 80% and if they go any more pale you would need to go the other way and increase, but I think you did it right - always go cautious first, easier to fix under feed than over feed!

Have you tried the method of putting a small hole in the stalk? This is Death simulation and causes the ripening trigger response to accelerate. Also what Grow3rPT said about Darkness stress harvest. They need a week or two to gain more mass, just wait and watch the stem fill up with colas. Impeccable setup, Quite fine life support your providing for the plant. Awesome grow fam.

If you flushed before just let em grow for that Week without feeding and you should be fine👍

I would say you are in the harvest window depending on the affect you want. If you want a more sedative affect you could go another week or more but for uplifting I would harvest this weekend.