I think QuestHelper will show you everyone's progress when you hover on a quest mob or corpse. This is fine for killing quests. In Howling Fjord there is a quest to free people from spider cocoons. In cases like that it doesn't show progress and yes, I ended up with 2 characters not having the quest and I only noticed after I turned in and wanted to equip the quest reward on all characters.

Thankyouverymuchquestmobonaplatformwithalittlenarr owramptogetupthereandnumerousthinpoleseverywhere. Quest designer was *NOT* a multi boxer.