Birger, I had an idea, about how to progress the EGUSFM to the "next level".
Firstly, regarding taking it one step further, I think the EGUSFM should consider - with stock 1.08 (no mods) consider including a series of flagname events bundled with the EGUSFM that work with stock paradox events, the respective choices taken by players during the game, and the historical coats of arms/flags that were actually used by the countries in question. England for example would be an excellent example of these (several) CoA changes throughout the game history. I, or any number of players here, would help in writing the events based up the CoA's created. You could also provide a similar service for the various mods out there but I guess this, and the mod version, may never happen or may not occur for some time.
If you don’t plan on doing this I wouldn’t mind working with you to do the more common nations in a separate "bolt-on".
Just some thoughts.