Most of the MT era maps include both the Solomani Confed border AND the Imperial border in the area of Sol. Ownership of that triangular chunk, and the disposition of the Vegans within it, are really the only differences, as the only other border not set for some time is in the Marches, and the 4th Frontier War will have just concluded in 1000, so that border is as found in later maps.
As for other races, the K'kree, Hivers, Zhodani, and Aslan are all pretty static in the Imperial neighborhood (you could peel a few worlds off the Heirate at the spinward edge, but who's going to notice?), with only the Vargr really changing polity borders much...