Thosha Yeah, that seems to be about it. I also loose 1 Point of Kerannii Score in Gawnfall (which requires Aram 16+) but this doesn't change the Gawnfall outcome (but it might still affect interactions with her later on).
While Zirantia score is really hard to increase in Ch4, the personal quests, buildings and choices in ch5 make increases no longer that rare and i didn't note any score misses (in ch4) caused by that loss.
Its also likely possible to completely skip the Embassy even for the ch5 annexation of Eustrin: Just before the Great Thenoursan War, i can give Aram+4 points (Magical Standards favored nation +3, Air Ship Trade: Eustrin also has Aram+1 effect) which seems to be enough to get the 2nd best control score and reach the threshold. However i didn't test this part yet.