Recently I gave the 1938 campaign a spin, and found it both intriguing and slightly disappointing. It was intriguing because it did allow a player (I was playing as the Allies) some choices in how to prepare for the war, but it was disappointing in how few choices you were actually permitted. Mostly the 1938 part of the campaign consisted of watching the historical sequence of events play themselves out. It seems to me that if we're going to go to the trouble of taking the game as far back as the beginning of 1938, an idea which I applaud, then players should have more room to shape the balance of their forces, prioritize research over force readiness, and so on. I don't know if a slightly more sandboxey environment would require some substantial reworking of the basic game engine, but I would like to encourage that such a direction be taken. It would give players more incentive to begin in 1938.
My other thought concerns what seems to me to be a slightly bumpy transition from the 1938 campaign to the main game in September of 1939. I saw to my surprise that when the Germans begin their attack on Poland they leave the western border with France largely unguarded, making it quite easy for the French simply to advance towards the Ruhr. There were a number of other surprising developments as well, such as Germany declaring war on Switzerland before they had even finished Poland off, and Italy entering the game by declaring war on Syria and therefore on France. When I restarted the game and checked the available scripts, I saw why this was the case, with dozens and dozens of scripts activated for all sorts of plausible and implausible variants from the historical war. This came as a big surprise, especially when one considers that the number of scripts activated for the main campaign are quite few, apart from the many decision events that pop up at fairly predictable times.
So if this mod gets further refinement in the future -- and I really think it should for the reasons stated above -- I wonder if it would be possible to switch off the more improbable historical variants on the start-up menu, allowing the player to have a certain amount of freedom without having to prepare for odd developments like the invasion of Switzerland.