the supermarkets in my area are huge climate controlled monsters, it makes absolutely no difference what the outside rh is, inside the store its 72F and 50%rh, forever
and while plants are not sheets, lower rh makes things dry faster.
i keep it at 40% rh in my house, and run a cool mist humidifier in my veg tent to keep it about 60% rh in there. the flower tent gets down to about 35% rh, which is lower than i like, but i know i'm not going to get pm or bud rot.
i use a small enclosed area to dry in, it stays about 72F, i keep it at 65% rh, and have a fan that changes the air out every 2 hours. it works for me, i get good smelling, good tasting weed, that burns nice. if i tried open air drying, i'd get dry, harsh, crappy tasting weed. i know this, because i tried it first, thats why i went to the trouble of getting the humidistat and all that