I didn't notice any mob nerf as well. completing 5 miniboss in musoleum is not that hard. mini boss can spawn in muso 1 and 2. people don't look for them. instead they go one way straight to boss like in graveyard. also in musoleum you can find multiple miniboss in muso. if its in muso 2, mini drops 2 tokens as well. it worth to run musoleum instead of graveyard