Yeah, heat stress can cause 'cupping' of the leaves. If anything you could use a touch of N, but late in flower, not to bother.

I'd use a little less Epsom... like 1/4 teaspoon/gal... enough to do the trick and not hurt if it isn't a problem.

Keep on forgetting to ask, is your new avatar a sled dog in its travel house?

Awww!