Sebastopol burger spot Lunch Box is experiencing a massive wave of new customers after being featured on KQED’s “Check, Please! Bay Area.” According to the Press Democrat, owners Derek and Megan Harn report daily sales spiking between 50% and 100%, driven by out-of-town visitors lining up to try their signature Oklahoma fried onion burger. The sudden midweek rush has even forced the popular eatery to sell out and close early on select days to re…