I am in my 4th playthrough, only 2 completed. I did not notice any diffculty change in battles except minor tweaks (the source spider in black cove e.g., before change significantly harder water attacks but no minions, now less severe water attacks but 3 mini spiders added).

Boreas was easy the first time and is easy now. The wolves, I just ran accidentially into them with a party level 5 and without the hound support, were always easy, the main challenge is to keep the one character alive that they focus on with their speed.

Sorry, I disagree. No major change. If fights become much easier you changed tactics or have a better skilled party. Quite normal.