Disclaimer: I was never down there, but took a google street view tour of their mainline. It seems there are a lot of crossings that are near major intersections (4 lane+ road crossing another), with traffic lights, slip ramps, etc. Then you toss in high speed trains? Correct me if I’m wrong; those that have been there.
I don’t want to see it of course, but I’m afraid that there’s going to be a bad grade xing collision, and there will be slower speeds imposed on Brightline as a result.