After much consideration, I halted construction on my layout, based on Thrice Around the Room. The layout just had too many curves for the space I had available, and I was unable to keep the minimum radius O72.
With all the time I had invested now being more or less wasted, I took a deep breath and called Roger Farkash at Trainworx. In the photo, I'm reviewing the first draft of the plan with George Watson and Roger. Roger is so good at this that there will be only minimal changes.