Yeah pretty much this.
Terraria Community Forums
Orchamut
CTNC
Journey Mode lets you set difficulty to anything from 0.5 to 3 times Normal Difficulty. (2 is Expert and 3 is Master) You could try Journey Mode on something like 2.5 times or set it to Master Mode Difficulty just for bosses.
Fuegomech
I got 99 problems, Curroptors in Master Mode are like at least twenty of them