For the vinaigrette: Place the prepared chiles a few pieces at a time on a comal (or iron griddle) over medium heat and dry roast until fragrant, about 30 seconds per side. Soak the prepared guajillo chiles in hot water until soft, about 15 minutes. Place in a blender along with the chipotles en adobo, orange zest, and vinegar, and pulse until the chiles and zest are finely minced. Add the ginger, oregano, allspice, onion, and sugar. With the blender running, slowly add the vegetable oil until emulsified.
Add salt to taste. Set aside until needed. Whisk or shake well right before using.
To prepare the shrimp: Peel and devein the shrimp. Place the avocado oil in large pan over medium-high heat. When the oil is hot, add shrimp and cook, frequently stirring or tossing, until just opaque, about 2 minutes. Be careful not to overcook. Remove the shrimp from pan. Season with salt and guajillo chile powder to taste, place on a warm plate, and loosely cover with foil.
To assemble: Toss the romaine lettuce with just enough vinaigrette to coat. Warm the tortillas on a dry comal, iron griddle, or skillet until soft and pliable. Place the tortillas on individual serving plates, 1 per serving. Top with the dressed romaine lettuce and shrimp, 4 per serving. Garnish with the cherry tomatoes, 4 halves per plate, and microgreens to taste. Drizzle a little more vinaigrette over the top just before serving.