Wow! I must be way out in left field as my method is quite different. Wings come out great in minutes on my Performer. Can't say I have tried to cook them on my Spirit, but it should be similar. This method is found in the Cook's Illustrated grilling book. First step is medium fire. Cook indirect for 4 minutes covered, then turn for 4 more minutes covered. Then put the wings on direct for a minute or at most 2 on each side uncovered, paying attention so you don't burn them. Off the grill, cover and rest for 8 to 10 minutes. I toss them in a salad bowl with the marinade right away that is before the rest period. Another approach is to leave them naked and serve with a variety of dipping sauces. Dipping sauces are very popular with crowds. This method gives juicy wings on the inside with crispy outside and great flavor.
Bill