I don't think it is doable, and I am a very fast walker in this neighborhood. I doubt Slave Play will start at 3pm, it will start more like 3:10ish with Covid check delays. It's two hours. So if you stay for the whole thing and miss the bows you still won't get out till 5:10 or later, and by then Phantom will have started. The walk is just under .5 miles between theatres, Google suggests 9 minutes. I could do it faster and maybe you could too if you run. Why not try a test walk and time yourself to see how fast you can do it before you come into the city?