While I think, 84 f is not the end of the world for a plant, however…you can see the end from there... I've had heat stress in the past, your thermometer reads 84 f… it’s 88+ somewhere in your tent… is your thermo at cola height, or lower?… I like the idea above has with switching lights to off hours, you could save a degree or two, that could be enough… osculating fan to blow gently on tops… more exhaust out the heat… is about all you can do…
My heat issues STOPPED, the minute I dialed in my AC units…
Good Luck!