I have increased my EMS (Effective Military Strength) by Coalesced.bin editor and now it is about 11500 (reduced it to half cause my readiness is 50 percent, don't have time to play multiplayer) and I can also convince The Illusive Man to commit suicide, but nothing else has changed. I can not see the other ending, I have only 2 choices.
The strange thing is that the 1st time I finished the game (that time my EMS was near 6000), I had 3 options (all endings) but I chose to destroy The Reapers and after that whenever I have checked, only 2 options were available, even your solution did not work.
Best Answer
Effective Military Strength is in fact LOCKED when you start the Cerberus Headquarters mission. BEFORE Priority Earth. This is the moment when you tell Hackett you're set and ready to attack. Simply editing a file and loading up your last save would not reset the locked value unless that save was made before the LOCK-IN action.
Edit the value and load an save before Cerberus Headquarters.