Trim excess fat from steaks, rinse meat in cold water, and pat dry. Brine overnight in a chilled bath of 3:1 water to beer, plus 1 cup salt and 1 cup sugar. Remove tomahawks from brine 2 hours before cooking and rest on counter until near room temperature.
Preheat grill using the two-zone method by turning burners to high on one side of the grill while leaving the other side off. Meanwhile, rub the pork in olive oil, season liberally with the BBQ rub, then roll the tomahawk edges in a blend of the coffee grounds, garlic, onion, and pepper. Season additionally, to taste, with kosher salt.
Lay the chops over coolest grill grates, bating, rotating and turning intermittently until internal temp registers 130F. Move to hottest, directly heated grill grates and char beautifully, until internal temp has achieved 140F. Remove from the grill, loosely tent with tin foil for 5-10 minutes and allow carry-over energy stored in the steaks to finish the cook - serving temperature at 145F.
To plate, carve tomahawks alongside the bone, removing the meat, then slice the steak in 1/2" cuts across the grain and on a bias. Plate the chops atop a bed of charred vegetables and alongside a beautiful fall salad. Garnish with fresh herbs and serve.