Ok, I've messed a bit with these two bytes and figured that they control most of the progress at Centra Ruins on the way to Odin's chamber (making the console at the bottom of the tower appear, stairs leading to top etc), but I haven't found yet what needs to be changed to disable this flag after Odin is defeated.
Do you still have the Cheat Engine table you mentioned at the top of
this wiki page? It looks like the download is no longer available. I guess it could be helpful and speed things up a bit.
Thanks for your help so far.