Everything started going to crap for me when I got to the Salt Lake. I don't know if enemies are starting to level up with me, but the jump in difficulty is extreme. I'm fighting lefties and righties that are casting Meteor and slapping me for 2500 damage. I swapped in Zell and Irvine to try and get them some levels, but the enemies were still brutal. Each fight has become a slog. Abadon was a piece of cake, though - I used one triple and had Edea, with her 198 magic stat, hit it with about 10 or 12 Curagas while Squall healed and Selphie supported/mugged/drew my third and final stack of Quake/did damage. 80k HP felt spot on. Damage felt spot on because it was fast - one of the first fights where I really felt the need to use haste. But it's way easier than the quad lefty/righty encounter, that's for sure.
Edit: I ended my run in the final Laguna flashback due to all the rough RNG I was getting. Death/Stop spam despite status junctions, one-shot crits...yeah. Ran out of time, too, but maybe I'll finish it at some point. Great job on the whole (the whole run felt spot-on except for the prison fight, IMO, and that last Laguna sequence).
You hit on something I'm running into. Several of the random mobs seem overly powerful for their purpose in the game. For instance, in the sewers at the end of Disc 1, the Creeps were massive hassle to deal with given their resistances, quick ATB, and a heart attack that hits for 1,500. I just auto-escaped any battle that had them. Similar situation with the 2nd Laguna section when he goes to the Lunatic Pandora. The Esthar Soldiers and Gespers would 1-shot my guys if I was back-attacked at the start.
I don't mind increased difficulty over the original (one of the reasons I wanted to try the mod). But, it seems several of these enemies are just difficult for the sake of being difficult. Having a group of enemies get 2 or 3 full ATB cycles waiting for a GF to come out is honestly just annoying. Most of the time so far, my GF's are nearly guaranteed to be killed if there's 4 enemies on the field given the sheer number enemy attacks that are going to go off. If there's only 2 party members, it feels like a waste to even try to summon GF's as they're basically canon fodder against large groups.