Welcome back Michael! Good to see that a new layout is on the way.
I remember the old plan. Lots of popups at first that you reworked to make pretty functional, and you did western scenery very well, IMO.
IIRC, you run big modern diesels and occaisionally some big steam. And industries tend to be larger too, since they are made from modern kits.
I think your chosen plan is very good for the space, which is limited given your druthers. You need broad radius curves, IMO, and a walk-in plan would simply not allow that in your given space.
Given that its a duck under in a small space, I would want an area for a small workbench under the layout, so I wouldn't have to pop in and out of the layout just to do some quick work on equipment. I would build the layout fairly high, about 54 inches, and place the bench under the layout's narrowest shelf, which is on the left side.
As another has mentioned, use of a rolling chair would be helpful, so I would want plenty of space in the middle like you have planed. I would refrain from adding any type of peninsula to the middle pit.
Looking forward to following your iterations and progress. Thanks for sharing.
Edit: Just taking a quick look at the track arrangement, I think some of the angles you used for turnout frogs are pretty aggressive and unrealistic for #6 frogs. You may have plenty of space to fit what you want where you have it, but I think some of the turnouts your drew would require more linear inches than what you have drawn.