I’ve heard from players of G40, that extra income only meant a longer game.
But perhaps GW36 has that room in which to spread troops. I agree with the premise behind what you are attempting to do, give more purchasing power to nations.
Myself I have approached this from the opposite angle, I’m giving more bonuses to nations instead of +1 to the value of all territory.
For instance, Japan gets a 1/2 IPP point per island, the idea being; how much utility is a sandy beach and jungle in the middle ocean.
This serves to encourage Japan to go Pacific.
Britain likewise gets a bonus for every neutral nation existing in Europe with connection to Britain, thus encouraging Britain to stand for democracies of small nations against the aggression of the Soviet and Axis threat.
Germany gets Waffen SS Infantry which if participating in an attack that captures a territory for the first time, boosts that territories income up +1 for only one turn.
Soviets get a +1 for each foreign capital and victory city it holds.
Many more in the same vein, I agree it adds to complexity, and requires everyone to go over their bonuses turn by turn, but it also makes certain parts of the globe attractive to different nations and nearly meaningless to others.