Shorten or remove cutscenes / animations that simply delay for previously defeated bosses
It is one thing if it is to improve the experience and provide additional lore for the first time of fighting and defeating a boss, but after having fought a boss once or multiple times it just starts to feel unnecessarily drawn-out to wait out cutscenes and animations, especially when it comes to lore-related ones there isn't much of a point to see them repeatedly.
Granted in case of multiplayer not every player may have fought against a boss yet, but even then I believe some kind of check/trigger could be made to differentiate between players who are fighting a boss for the first time on a world and those who have already defeated them at least once. Alternatively or in addition to that maybe there could be checks for where/how the summon idol is placed/positioned, e.g. in the center / on the summoning symbol vs next to the symbol.