Brown the bacon in a pan over medium heat until much of the fat is rendered, but the bacon is not fully crisp. Add the smashed garlic cloves and continue to cook until the garlic is fragrant, about 30 seconds or so. Drain the bacon and garlic into a small bowl lined with paper towels. Reserve about 1 tbsp of the bacon, and set the rest aside.
Fit your food processor with the shredding attachment, and shred the cheddar, swiss, and gouda cheeses together. Remove about 1/2 cup of the cheese and set aside. Remove the shredding attachment and install the chopping blade.
Add the cream cheese, garlic-bacon, green onion, dry mustard, and cayenne pepper, and process until combined. With the machine running, pour in the beer and continue to process until the mixture smooths out and appears well blended, about 10 to 15 seconds.
Scrape the mixture out into a baking dish and top with the reserved cheese. Bake until the mixture is heated through and bubbling, and the top is lightly golden brown, about 30 minutes. Remove from oven, top with the reserved bacon, and serve immediately.