By Evan Bleier Opened in San Juan Capistrano in Orange County in the summer of 2020 as the pandemic was wreaking havoc across the U.S., chef Daniel Castillo’s Heritage Barbecue faced challenges, like many restaurants, from the moment it opened its doors. But, Heritage — which dishes up everything from brisket and spare ribs to smoked tri-tip and char siu pork belly and routinely sells out of its offerings — also had difficulties before launch due to Castillo’s insistence on using traditional offset smokers. The brainchild of Castillo and his wife Brenda, Heritage had to battle it out with city…