They released iDungeon AFK, which makes a character sit at the first room while the iDungeon Pro main completes the dungeon. You both get exp. I only received a -7% exp deduction from it.
Everyone has problems with Yk-lagor, as well as the Runebound Behemoth and occasionally Blink. There is a thread on RSBuddy with the current status of how iDungeon Pro handles bosses, but I can't find it right now.