I''ve successfully reentered Tohoku...
This is largely possible thanks to the utility that was released a couple days ago that converts saved game files into readable text. It's simple--after translating your saved game, open it and go to the header that says [mPlayer. After this are going to be 5 or so lines that start with "locked_gate =". Just delete these lines and thats it.
I went back to the Tohoku system, and I realized that there isn't much there. You can land at Ryuku base, but there are absolutely no people on it whatsoever. You can still sell equipment and commodities, but you are going to have to do business with the ghosts who inhabit the base . Tekagi's Arch was also nice to revisit, but it was still hostile with me even though it's labeled as a Kusari Navy base (which I am normally friendly with). Now I'm off to Omicron Minor...