Preheat the oven to 350°F. Whisk the mayo, lemon juice, hot sauce, fish sauce, salt, pepper, and smoked paprika in a large bowl until smooth. Gently fold in the lobster, artichoke hearts, gruyere, and cheddar. Butter a shallow 8-inch gratin dish (or any oven-safe baking dish), add the mixture to the dish and top with the parm. Bake until golden and bubbly, 15 to 20 minutes (if you want more golden color on top, jack up the broiler and broil, watching carefully, until you get the color you want, 1 to 2 minutes). Remove from the oven and sprinkle with the paprika.