I live in South Florida daily temps run 75- 92 during the summer. I am considering getting a chest freezer and want to put it in my garage. It gets hot in the garage even through the ceiling has 30R blown in insulation. I thought of building a foam cover for the freezer to help keep it colder. I would make sure I didn't cover the air intake or exhaust for the compressor. Does the hive think it would work?

Don't build anything around the freezer. Freezers need air flow around them. The coils that are giving off heat are usually in the outside walls of the freezer. The outside of the freezer will give off heat when it's running.

I have a deep freeze in my garage. Its a well insulated garage and when we park the wife's vehicle in the garage, it gives off a lot of heat. It's regularly over 100 degrees in there. We installed a heat pump water heater next to the freezer and it has dropped the temp in the garage a little. It's still warm in there.

Easily maintains sub zero temps year round.

I do wish that freezer manufacturers would use another inch of foam around the freezer box and put foam in the lid (most put fiberglass in the lid and foam around the box.

Unless the chest freezer is a commercial style with forced air fan cooled condenser , typical household style uses the outside walls of the chest as the hot side, and the insides as the cold side. Purely convection heat exchange, the chest needs a couple inches of free air flow around the outside or it can't work. You could set the unit on a slab of foam, and put foam on the lid, but not the sides.