Over the last 8 years or so I was in the process of setting up my own 8' by 12' layout but I realized the problem of access to all parts of it without having to walk on it. I then decided to create space right down the middle with about 20" between two 4' by 12' sections On either end of the separation (12' long) I used bridges which for the present I duck under. I could reach everything on one of the 4' by 12' sections from 4 sides but the second was against a basement wall where I cut approach it from three sides. My solution was to have a small step ladder so when I stood on it I could reach over almost 4 feet. I did build the table top strong enough to walk on.
Maybe in your planning separate your 8' by 12' set up into 2 4' by 8' sections. The pictures in the entry above is a modified version of this.
John
