Good question Larry. It is true that your elevator when moved 1/16" an inch, would only now be even with the stab surface, but, the airfoil has changed, and therefore the lift generated by the combined surface of the stab and elevator. It's because the airfoil formed is more like a lifting airfoil rather than the symetrical arfoil we started with.

It would appear that near, and around nuetral, the lift generated would be smaller than when the elevator is deployed more, acting like a greater  and greater undercambered airfoil. If this is so, then the effect may be quite desirable, acting somewhat exponentially.

It's similar to, using a thicker stab  so the elevator is less effective around nuetral, though not as drastic.

The largest draw back to the thick stab method of trimming, is that when the elevator is blanked out by the thicker stab, there is often a hesitation that is very apparent at the intersections of manuvers such as the Eights.

Well Larry, I believe the surfaces will work fine as a plank. In fac, I've seen planes finished that way, with no taper at all on the movable surface.

Aside from not looking finished to me, I would assume that the reaction to control input would be minimally faster than tapered surfaces.

In my experience, the flat/plank elevator (same thickness as the stab) may have a problem opposite to the hesitation problem--oversensitivity around neutral with difficulty tracking in level flight, especially if the controls are set up on the sensitive side, and the pushrod hole in the horn is not a bit oversize.

One of my 1/2A stunt airplanes had a built up 1/32 sheet covered 1/4 in thick plank stab and elevator.  It flew to suit me. Perhaps a more important question is whether the trailing edge should be square or rounded.