the pop-ups out here are vends, not sit down. There are many different types of pop-ups. You are really doing a vend situation, where you are selling food to people who are going to come by. More like a food truck than a restaurant. The biggest key is marketing and social media outreach, as you will need to draw people. Walk-ups rarely work well enough to justify the cost of opening.
Again, you will need to gamble a bit up front, and cook what you think you can sell. Fortunately, most folks love the idea of being the first to discover the next great thing. You can leverage that with social media and flyers, so people get the buzz. Go heavy on the items like pulled pork as you can freeze and eat it yourself over time. Ribs are harder to vend, and don't hold nearly as well.
Our experience with vending was that you can use a premium item like ribs, sell in small plate form (meaning 3 bones, one side) and not selling racks until verbal demand increases. You can cook a little less initially, and stay open longer.
I'm feeling bearish, and I'm packing a Wusthof Grand Brisket slicer from MABA
Whip It Off, Chambers!
"perhaps...but then again...maybe not..."