So I tried out the changed bosses on my test character. I still think they are unfair, but not nearly as bad as before. The biggest issues I still have is imposing mana sickness on you, which singles out gimping magic weapon users, the projectile spam, and the fact they move so much for being very small targets. By comparison, the Lunatic Cultist is as small as the player, but only sometimes moves around and mostly floats in place. It seems like homing weapons are the only real way to deal with the current bosses as they are. If they moved much slower or even stopped from time to time, they would be far less annoying to hit.
I don't know if this was in previous versions, but I noticed all yoyos are converted to throwing weapons. However, they are still also set as melee weapons and not just throwing alone. Furthermore, the method used affects most flails and all power tools. I'm not sure taking away yoyos from melee users is a good idea. That seems like it's better left to other mods that only make that change, not mods like these that add content to the game.
It seems like a challenge mode item was added and that by default, you no longer get a debuff from being in outer space. Good, because I Found that highly annoying for earlier game sky island hunting before.