I've decided on a 12" square modular system, ultimately enabling a 6' x 4' table arrangement with up to 4 separate entrance sections.
Here are the first two trial pieces.
This one has three entry points, a 2" wide and in a T shape, 2 4" wide door ways.

This one is a corner entry arrangement with both 4" wide and a set of rooms on the outside corner.

Plenty of thought to put into the clutter that needs to go along walls and inside the rooms....