Agreed.

I was in there solo today and I disconnected on like 50 something so it ruined the entire file of like over 2hrs spent.

They just need to make it so the instance doesn't close for maybe 10 minutes to give the player a chance to log back in. It likely wouldn't be able to be abused since if you had an enemy on you it would kill you anyway when you disconnected since your character stays there for a bit on the server.