How to Make It
Coarsely chop 6 of the scallions. Place chopped scallions, ginger, lime juice, thyme, garlic, chile, allspice, and 3/4 teaspoon salt in a food processor. Pulse until a coarse paste forms, 6 to 7 times, scraping down sides a few times between pulses to evenly incorporate.
Melt butter in a small saucepan over medium-low. Whisk in jerk paste until combined, and remove from heat. Reserve 1/4 cup jerk butter in a small bowl for serving.
Preheat grill to medium-high (400°F to 450°F). Toss together canola oil and remaining whole scallions in a large bowl; season with pepper and remaining 1/4 teaspoon salt. Place scallions on oiled grates, and grill, uncovered, turning occasionally, until lightly charred and tender, about 5 minutes. Set aside.
Using long metal or wooden skewers, skewer lobster body halves lengthwise. (This will help keep them straight while grilling.) Brush lobster meat evenly with about 2 tablespoons remaining jerk butter. Place skewered lobsters, meat sides down, and reserved lobster claws on oiled grates, and grill, uncovered, until shells begin to turn red, about 4 minutes. Flip claws and bodies, and brush cut sides of tails with remaining jerk butter. Continue grilling until meat is cooked through, about 4 more minutes for bodies and 5 to 6 more minutes for claws, turning claws occasionally. Remove from heat, and remove skewers.
Arrange lobsters and charred scallions on a platter. Gently rewarm reserved 1/4 cup jerk butter, if needed. Serve lobster tails and claws with jerk butter and lime wedges.