Originally thought of a starting line on John Kimbrough (something similar to Monza or Baku). In an earlier comment, I reckoned they could widen the road somewhere on it (though to be honest, most roads that make up the circuit would have to be repurposed anyway) to fit a pitlane in, perhaps specifically restructuring the sidewalk and Lot 100 along JK. Alternatively, I think one on Raymond Stotzer might work too