Well, first let me say that most of our games end up in Axis victories, and that usually happens within 7-9 rounds. The games that have been Allied victories usually take longer, about 12-13 rounds or so.
If Japan is doing a decent job of keeping USA busy in the Pacific, and if they manage to take Calcutta and the DEI then they should be able to, then the US isn’t going to be all over the Atlantic and Med. In that case, Germany will probably be SBRing and convoy raiding UK into the poorhouse while driving deep into Russia and Italy will be taking advantage of a weakened Britain and taking many British territories throughout Africa and the Middle East. It will just get harder and harder for Britain to reclaim those territories. THIS is the case where I think UK needs another NO or 2 so they at least have a chance at bringing in a little more income.
Now, in the case of games where the Allies are doing better, then I agree UK will be making plenty of money. Odds are in that type of game, America has managed to at least neutralize Japan and is more heavily invested in Atlantic/Med operations. Germany will probably be stretched thin trying to keep Allied navy and air force at bay while dealing with Russia. Italy probably has gotten pushed out of Africa, lost their fleet in the Med and is cornered in Italy. Then UK will probably be very strong and doesn’t need to have another NO or two. This will probably be late in the game as well. My problem is with the early game, when UK has very few options. I still think they should have more than just one NO opportunity.