"If you are going to do some work for a while in a particular small region of the model you can reduce the grid size for a while and relocate the grid if needed by using View > CPlane."

Ah!

This is what was wrong with my workflow when using MoI3d. I understand now. I just assumed that the Grid settings would work under any circumstances and also when switching to other components inside the same scene.

Thank you Micheal, I think that this is the answer that I was looking for, to better understand how to work with the Grid settings inside MoI3d.

The way i would handle this would be to setup an "assembly" type workflow.

So MoI allows you to launch multiple, concurrent sessions. I would have one file with my overall scale. Then others can be created for whatever the current need is.

Copy and paste between the 2 works like a charm.

So with this, i can have a 64 story building, and model a tennis shoes shoelace eyelet, on the 34th floor, next to the cup on the window sill......

That's a good idea. Thanks for the suggestion.