Jeff, I really like the improvements you've made to the plan. If I may offer a couple of tips to enhance the 3D aspect of SCARM.
Terrain Control Options: Normal, Wireframe and Off. Here are two examples. The red arrows point to the controls for each within the 3D window.
Terrain Off
Wireframe Terrain
The attached SCARM file, which is the same track plan as Jeff's #5, has two small suggestions one of which can be seen in the 3D Wireframe above. Moving the tunnel portal in the foreground out a bit more from the track switch above it will help with the portal fitment. Commercially available tunnel portals (MTH and K-Line) outside heights range from around 8" to 8 1/2".
Also in this attached SCARM file, I took the liberty of removing selected upper level track supports which were coinciding with lower level track and under the otherwise unsupported parts of the Double Track bridge. These removals allow viewing the lower level tracks in 3D mode more clearly when the terrain is transparent.
Here's how to remove or add Track supports. Note that the Track Heights have to be turned on to access this option, as indicated by the Red Arrow.
I hope this is helpful.
