Am I right about stereo limits and enchanement?

"Apparent 3-dimensionality" is both a perception issue, and a comfort issue.

If you wish to show 3-dimensionality of a narrow range of far elements (say objects 100 feet away out to infinity) with comfort, you must use a wider seperation, else the elements may appear "flat".

If you wish to show 3-dimensionality of a wider range of elements (say, 1 foot to infinity) with comfort, you must use a smaller separation, else you will have an uncomfortable view.

If you wish to show 3-dimensionality in a very narrow range of closer elements (say, 4" to 8"), you can use either a small separation, -OR-...

You can toe-in the cameras so the important elements remain centered in the view, using a normal (or even wider) separation, and correct resulting keystone distortion in software in post process. This will enhance depth ("3-dimensionality") of the result than otherwise produced by a small separation, with the penalty of cropping out significant amounts of the edges of the frame during correction.

The situation you discuss has been called "depth budget" by stereo moviemakers. You need to adjust interaxial, and sometimes toe-in, to assure the important elements in the scene are comfortable to view.

Actually, it would be optimal if the separation between the optical axes of parallel lenses (with a large image circle), and the separation of the sensors behind them, could be adjusted independently. This would reduce or eliminate toe-in and keystone distortion. Nobody makes such equipment, AFAIK...

Hope this helps????