It’s great that you’ve found a soil mix that works for your local area! Humidity and heat can tricky elements when dealing with succulents, but it does not make keeping them happy impossible.
Not all succulents love the heat, but some — like Cacti, Aloe, and Agave — can thrive in it.
While it may not be possible to control the weather, you can control where you are planting succulents, and what you are planting them in. If succulents are planted in the ground, you can use the rain to your advantage: wet soil helps to keep the succulent roots cool.
Adding more pumice to your soil will also help it dry out faster. You even can plant the succulents in all pumice in areas that get a lot of rain.
If you have your succulents potted, be sure that they are in planters with drainage holes. Pot feet are superb at allowing planters to drain, and placing heavy pots on a trolley can help you move them whenever the weather turns poorly.
Also, Bonsai Jack is just down the road from you about an hour in Fort Meyers. If you need pumice in larger quantities you can pickup locally from him.