I've played dozens of hours with this mod, but finally uninstalled it due to buggy behavior and extreme balance issues.
Affixes have a tendency to break enemy AI, get enemies stuck in blocks, and make enemies so large that they can't fit through regular gaps to reach you. Unreal Goblin Archers are a good example of an enemy that should be scary, but runs really fast into close range instead of shooting from a distance like normal. Other enemies have similar issues. The size altering affixes frequently cause problems while underground. Big enemies are often some of the least threatening ones you'll meet.
Any boss fight that's reasonably well balanced becomes incredibly punishing when any of the tougher prefixes show up. Bosses that are already punishing, like many of Calamity's bosses or Enigma's bullet hell bosses, simply kill you. A legendary Hypothema from Enigma is one of the most ridiculous enemies I've seen. I was quickly executed by a blue blur. Enemies like Calamity's Slime God are hit particularly hard by your mod, since there are a ton of enemies spawned that each become far stronger if given a prefix that affects movement speed. Due to the sheer quantity of enemies in that fight, it happens often.
Almost every single death I've had since installing your mod was purely due to your mod. Legendary Ice Bats swoop in at light speed for 100+ unavoidable damage, lightning fast bosses balanced to hit like trucks due to the ability to dodge them become so fast that they're undodgeable, and general damage buffs turn ordinarily dangerous encounters into one-shots.
I love the idea of your mod. It definitely spices up enemies that have grown stale over time. The bugs and negative interactions with game mechanics are annoying, but I could possibly live with them. The balance issues were just too much for me. The extremes are far too extreme, especially given the unpredictable nature of the affixes and their ability to spawn on bosses.
I don't know if you intentionally balanced your mod to include unavoidable deaths like the ones I've experienced. Some people do find that fun. If you didn't, though, my recommendation is to greatly scale back the buffs and debuffs. I didn't mention debuffs above, but they often trivialize enemies. Enemies like Ice Bats don't need to become godlike killing machines with top affixes. Bosses can be a bit more threatening, but many, especially in mods, are already well balanced or even overtuned.