After disassembly I cleaned the contacts of the LVDS cable with a gummy pencil eraser on the logic board side and on the display side. The flickering problem showed 95% improvement.

Next I shielded the display panel with aluminum foil on both sides to dissipate heat and then heated up the inverter board with a heat gun at 200ºC, working one section at a time. From this there was no noticeable improvement, but on reassembly I realized that screen flicker would result from light tapping with the flat part of the plastic spudger under the display panel between the metal plate that retains the inverter board and the inverter board itself (essentially tapping a bit in the horizontal slot to the left of the bottom left display retaining screw). Okay, problem area located.

I solved the problem by removing all 6 display retaining screws once again and then shifting the display upward. I made 3/4" x 2 1/2" strips of thin, doubled cardboard and then dropped them down into the slot on both the left side and the right side of the bottom left retaining screw. Then I slipped the display back down into position, the inverter board on top of the cardboard. before finally screwing it in I placed a third cardboard strip over the inverter board to the left of the bottom left retaining screw. Now the inverter board is sandwiched between cardboard on both sides. The problem is 100% solved. Shifting the display on the hinge back and fourth and even torquing the display with hands in diagonally opposed corners shows no sign of screen flicker whatsoever.