Place the pork in a zip-top bag. In a small bowl whisk together the soy sauce, lime juice, sugar, oil, vinegar, ginger, and cayenne pepper.
Pour the mixture over the pork and turn several times to coat. Marinate for at least 30 minutes but preferably several hours, turning occasionally to redistribute the marinade.
When ready to cook, let the pork sit at room temperature while the grill is preheating. If preparing the optional sauce, pour the marinade into a small saucepan and bring to a boil. Boil gently for approximately 2 minutes or until the marinade has thickened and reduced to 1/4 to 1/3 cup; set aside.
Cook the pork chops over medium heat for approximately 3 minutes per side or until the pork is slightly pink in the center. (Internal temperature should read 145 degrees F.)
Remove the chops to a platter and drizzle with the sauce or place the sauce in a small bowl and pass at the table. The reduced marinade also makes a flavorful sauce for mixed greens and complements most green and orange vegetables.