Hi,
You have done some beautiful work there, and a lot of it. Very, very nice!
May I offer a suggestion............ on my "fill the room layout" I put in triangles of plywood on all the inside corners. They range from 8x8 inches to 12x12 inches. This has done two things........it allows for a more sweeping curve (be it rail or road), and it softens up the harsh corner.
After figuring out the size of the triangle, I then put 1x4 fascia boards on the edges, and then fastened to the existing benchwork. The result is super strong, and IMO made a very nice difference.
Hope to see more pics as you progress!
Bill