I and a friend have been chipping away at Divinity EE for nearly 18 months and cannot enter the source temple in the Phantom Forest. The door says something is missing from the frame. We've got over 12 inert stones, we've ran through the list and got all 15 stones, we think. We've opened all of the portals at the end of time, the last being the chapel with Zix returning to his seat.
We've stopped the fireballs at the end of time. We've also sent the watch to Cyseal looking for the imps, seen the dialogue of the watch in Cyseal and told the imps of that action which completed that quest.