I searched for Frostsworn General, and Halls of Reflection, none that I saw mentioned this, but if it's a re-post feel free to link the post, and I'll delete this one.
Anyway, if the group stays in the first room where frostmourne was, and the tank (or in my case the engineer with nitro boots ) pulls the general all the way back to that room. Once there you may commence dps, if he's in that room he'll do the call for adds but they won't come.
Not much of an epic exploit, but anything I can do to make that instance faster is just fine by me. I can post pictures... But if you don't get it, pictures probably won't help.
As far as I know you don't need any speed enhancement to get this done as long as no one is dpsing, you just need to be able to survive the long pull, pretty simple for a tank even w/o hots, or ranged who just turns around quickly. The only thing to watch for is the spike he casts and the shield throw, but I've done it several times and never had a problem.